Loop Effects Research Articles

Global fit of modified quark couplings to EW gauge bosons and vector-like quarks in light of the Cabibbo angle anomaly

There are two tensions related to the Cabibbo angle of the CKM matrix. First, the determinations of Vus from Kμ2, Kℓ3, and τ decays disagree at the 3σ level. Second, using the average of these results in combination with β decays (including super-allowed β decays and neutron decay), a deficit in first-row CKM unitarity with a significance of again about 3σ is found. These discrepancies, known as the Cabibbo Angle anomaly, can in principle be solved by modifications of W boson couplings to quarks. However, due to SU(2)L invariance, Z couplings to quarks are also modified and flavour changing neutral currents can occur. In order to consistently assess the agreement of a new physics hypothesis with data, we perform a combined analysis for all dimension-six Standard Model Effective Field Theory operators that generate modified W couplings to first and second generation quarks. We then study models with vector-like quarks, which are prime candidates for a corresponding UV completion as they can affect W -quark couplings at tree level, and we perform a global fit including flavour observables (in particular loop effects in ∆F = 2 processes). We find that the best fit can be obtained for the SU(2)L doublet vector-like quark Q as it can generate right-handed W-u-d and W-u-s couplings as preferred by data.

The causal loop diagram model of flood management system based on eco-drainage concept

Flooding has been a recurrent problem in the Indonesian capital, especially in the northern part of Jakarta, along the Jakarta shore. The floods were caused by a number of sources. According to Renald et al. (2016), there are four critical factors in designing disaster-prone cities in Indonesia, namely spatial management, disaster adaptation, disaster mitigation, and technology innovation. Therefore, the development of infrastructure in Jakarta has started to use these four elements, by applying the concept of environmentally friendly drainage, specifically the concept of eco-drainage. This study aims to understand the general picture through the cause-and-effect relationship between all flood components. This study used a qualitative approach and was conducted using a dynamic system method to describe the Causal Loop Diagram (CLD) model, which provides information between interrelated variables and forms a complex system Rifaldi et al. (2021). The model generated from the dynamic system can be used for scenario analysis by showing how the interactions between the components that make up the structure of the system and the effects of feedback loops affect. The CLD model shown shows that the use of eco-drainage will directly affect the condition of 2 (two) other variables, both of which will lead to one main variable. The proposed settlement scenarios will result in policy and technical recommendations. This CLD model shows that the interaction between variables is very dynamic and affects each other massively and holistically. Combining dynamic system processes with SMWW can potentially improve the expected results in engineering and provide an alternative scenario.

FAK/IL-8 axis promotes the proliferation and migration of gastric cancer cells.

Gastric cancer (GC) is one of the most common malignancies in China and is associated with high mortality. The occurrence and development of gastric cancer are related to genetic and environmental factors. Focal adhesion kinase (FAK) is a cytoplasmic nonreceptor protein tyrosine kinase that is activated by the extracellular matrix and growth factors. FAK is highly expressed in cancer and promotes its development by regulating cancer cell proliferation, migration, and angiogenesis. The expression of IL-8 is increased in many types of malignant tumor cells and is linked to their proliferation, migration, invasion, angiogenesis, and EMT. In this study, we found FAK to be essential for the proliferation, migration, and peritoneal metastasis of gastric cancer cells. To examine the molecular regulatory mechanisms of FAK in the peritoneal dissemination of gastric cancer, we performed RNA-seq analysis of MKN-45-FAK-/- and MKN45 cells and demonstrated that IL-8 was downregulated in FAK-deficient cells. Conversely, we confirmed that IL-8 activates FAK activity. We established that IL-8 promotes the proliferation, colony formation, andmigration of gastric cancer cells that are partially mediated by FAK. Thus, we propose that an IL-8-FAK-IL-8 positive feedback loop effects the proliferation and migration of gastric cancer cells.

Good vibrations: tactile cueing for freezing of gait in Parkinson’s disease

BackgroundCueing strategies can alleviate freezing of gait (FOG) in people with Parkinson’s disease (PD). We evaluated tactile cueing delivered via vibrating socks, which has the benefit of not being noticeable to bystanders.ObjectiveTo evaluate the effect of tactile cueing compared to auditory cueing on FOG.MethodsThirty-one persons with PD with FOG performed gait tasks during both ON and OFF state. The effect of open loop and closed loop tactile cueing, as delivered by vibrating socks, was compared to an active control group (auditory cueing) and to a baseline condition (uncued gait). These four conditions were balanced between subjects. Gait tasks were videotaped and annotated for FOG by two experienced raters. Motion data were collected to analyze spatiotemporal gait parameters. Responders were defined as manifesting a relative reduction of > 10% in the percent time frozen compared to uncued gait.ResultsThe average percent time frozen during uncued gait was 11.2% in ON and 21.5% in OFF state. None of the three tested cueing modalities affected the percentage of time frozen in either the ON (p = 0.20) or OFF state (p = 0.12). The number of FOG episodes and spatiotemporal gait parameters were also not affected. We found that 22 out of 31 subjects responded to cueing, the response to the three types of cueing was highly individual.ConclusionsCueing did not improve FOG at the group level; however, tactile as well as auditory cueing improved FOG in many individuals. This highlights the need for a personalized approach when using cueing to treat FOG.

Composite scalar boson mass dependence on the constituent mass anomalous dimension

We perform a Bethe–Salpeter equation (BSE) evaluation of composite scalar boson masses in order to verify how these masses can be smaller than the composition scale. The calculation is developed with a constituent self-energy dependent on its mass anomalous dimension ([Formula: see text]), and we obtain a relation showing how the scalar mass decreases as [Formula: see text] is increased. We also discuss how fermionic corrections to the BSE kernel shall decrease the scalar mass, whose effect can be as important as the one of a large [Formula: see text]. An estimate of the top quark loop effect that must appear in the BSE calculation gives a lower bound on the composite scalar mass.

Guide to anomaly-mediated supersymmetry-breaking QCD

We present a careful study of the chiral symmetry breaking minima and the baryonic directions in supersymmetric QCD ($SU({N}_{c})$ with ${N}_{f}$ flavors) perturbed by anomaly mediated supersymmetry breaking (AMSB). For the s-confining case of ${N}_{f}={N}_{c}+1$ and most of the free-magnetic phase (${N}_{f}\ensuremath{\le}1.43{N}_{c}$) we find that naive tree level baryonic runaways are stabilized by loop effects. Runaways are present, however, for the upper end of the free magnetic phase (${N}_{f}\ensuremath{\gtrsim}1.43{N}_{c}$) and into conformal window, signaling the existence of incalculable minima at large field values of $\mathcal{O}(\mathrm{\ensuremath{\Lambda}})$. Nevertheless, the chiral symmetry breaking points are locally stable, and are expected to continuously connect to the vacua of QCD for large SUSY breaking. The case of ${N}_{f}={N}_{c}$ requires particular care due to the inherently strongly coupled nature of the quantum modified moduli space. Due to the incalculability of critical K\"ahler potential terms, the stability of the chiral symmetry breaking point along baryonic directions cannot be determined for ${N}_{f}={N}_{c}$. With the exception of this case, all theories to which AMSB can be applied (${N}_{f}<3{N}_{c}$) possess stable chiral symmetry breaking minima, and all theories with ${N}_{f}\ensuremath{\lesssim}1.43{N}_{c}$ (aside from ${N}_{f}={N}_{c}$) are protected from runaways to incalculable minima.

Hadronic loop effects to excited scalar charmed mesons revisited

We re-examine the hadronic loop effects on the masses of and calculated in quark models in the framework of heavy meson chiral perturbation theory (HMCHPT). Unlike previous approaches, ours reproduces the observed scalar charm states reported by the Particle Data Group (PDG). We show why previous approaches of using HMCHPT in studying mass shift effects due to chiral loops gave unsatisfactory results.

The effect of umbilical cord loops around the fetal neck on the modified Doppler myocardial performance index (Mod- MPI) in a sample of Egyptian population.

The effect of umbilical cord loops around the fetal neck on the modified Doppler myocardial performance index (Mod- MPI) in a sample of Egyptian population.

Analysis of the Optimized Compensating Loops Effect on the Magnetic Induction Due to Very-High-Voltage Underground Cable Using Grey Wolf Optimizer

Analysis of the Optimized Compensating Loops Effect on the Magnetic Induction Due to Very-High-Voltage Underground Cable Using Grey Wolf Optimizer

The cost of an ALP solution to the neutral B-anomalies

The neutral anomalies in B decays are analysed in terms of the tree-level exchange of an axion-like-particle (ALP), within the effective field theory framework. The complete two-dimensional parameter space for ALP couplings to electrons and muons is explored. The solutions to RK and to the two energy bins of {R}_{K^{ast }} are confronted with the impact of ALP exchange on other observables (meson oscillations, leptonic and semileptonic decays of B mesons including searches for new resonances, astrophysical constraints), as well as with the theoretical domain of validity of the effective theory. Solutions based on ALPs heavier than B mesons, or lighter than twice the muon mass, are shown to be excluded. In contrast, the exchange of on-shell ALPs provides solutions to RK and/or {R}_{K^{ast }} within 2σ sensitivity which are technically compatible with those constraints. Furthermore, a “golden ALP mass” is identified at the frontier between the two energy bin windows of {R}_{K^{ast }} , which could simultaneously explain these two {R}_{K^{ast }} anomalies together with RK; this calls for the convenience of different energy binning which would easily clear up this (unlikely) possibility. The impact of smearing on data analysis is also discussed. When loop effects are taken into account, the solutions found can be in addition compatible with the data on the g − 2 of the electron but not simultaneously with those on the g − 2 of the muon. Furthermore, loop effects may require fine-tunings of some coupling values.

Power system small-disturbance stability analysis and control design: A characteristic locus method

A characteristic locus method developed from the celebrated generalized Nyquist criterion is proposed for power systems small-disturbance stability analysis and control design in this paper. First, a loop transformation is introduced to re-formulate the familiar Heffron-Phillips model. The new model has a feedback control structure so that the generalized Nyquist criterion is applicable when concluding the stability of the closed-loop system. Subsequently, the relationship between generalized Nyquist curve and characteristic loci is utilized to acquire a new stability margin. The effectiveness of the stability margin is demonstrated using Cassini Oval Theorem. An analytical expression of the stability margin is derived as well. It is convenient to quantify the effects of control loops on stability margin by applying this expression. Moreover, the analytical relationship between stability margin and frequency responses of controllers provides information for the design of the controllers. The utility of the proposed method is confirmed through case studies.

Noncommutativity and logarithmic correction to the black hole entropy

We study the noncommutative corrections to the entropy of the Reissner-Nordström black hole using a κ-deformed scalar probe within the brick-wall framework. The noncommutativity is encoded in an Abelian Drinfeld twist constructed from the Killing vector fields of the Reissner-Nordström black hole. We show that the noncommutative effects naturally lead to a logarithmic correction to the Bekenstein-Hawking entropy even at the lowest order of the WKB approximation. In contrast, such logarithmic corrections in the commutative setup appear only after the quantum effects are included through higher order WKB corrections or through higher loop effects. Our analysis thus provides further evidence towards the hypothesis that the noncommutative framework is capable of encoding at least some quantum effects in curved spacetime, although additional contributions will appear when the NC effects are fully incorporated in a gravity theory.

Effect of Tuck Loops on Fabric Properties of Cardigan Derivative Structures

Exploring the effect of tuck loops on fabric properties of some knitted structures was aimed in this study. Samples were produced on a Stoll V-bed knitting loom with 100% acrylic yarn. Five types of knit structures (1x1 rib, half cardigan, double half cardigan, cardigan and double cardigan) were knitted with identical machine settings. Test results revealed that double cardigan fabric has the highest fabric thickness, thermal resistance and coefficient of friction. Double half cardigan provides the highest air permeability, whereas 1x1 rib structure has the highest relative water vapor permeability, mass per unit area and loop length. Half cardigan has the highest bending rigidity. Half cardigan and double half cardigan both have the best pilling results. It was observed that test results of half cardigan-double half cardigan and cardigan-double cardigan are generally similar as pairs. However, dimensional, mechanical and comfort characteristics of 1x1 rib fabric seem quite different.

Influence of administration time and sex on natriuretic, diuretic, and kaliuretic effects of diuretics.

Sex differences in renal function and blood pressure have been widely described across many species. Blood pressure dips during sleep and peaks in the early morning. Similarly, glomerular filtration rate, filtered electrolyte loads, urine volume, and urinary excretion all exhibit notable diurnal rhythms, which reflect, in part, the regulation of renal transporter proteins by circadian clock genes. That regulation is sexually dimorphic; as such, sex and time of day are not two independent regulators of kidney function and blood pressure. The objective of the present study was to assess the effect of sex and administration time on the natriuretic and diuretic effects of loop, thiazide, and K+-sparing diuretics, which are common treatments for hypertension. Loop diuretics inhibit Na+-K+-2Cl- cotransporters on the apical membrane of the thick ascending limb, thiazide diuretics inhibit Na+-Cl- cotransporters on the distal convoluted tubule, and K+-sparing diuretics inhibit epithelial Na+ channels on the connecting tubule and collecting duct. We simulated Na+ transporter inhibition using sex- and time-of-day-specific computational models of mouse kidney function. The simulation results highlighted significant sex and time-of-day differences in the drug response. Loop diuretics induced larger natriuretic and diuretic effects during the active phase. The natriuretic and diuretic effects of thiazide diuretics exhibited sex and time-of-day differences, whereas these effects of K+-sparing diuretics exhibited a significant time-of-day difference in females only. The kaliuretic effect depended on the type of diuretics and time of administration. The present computational models can be a useful tool in chronotherapy, to tailor drug administration time to match the body's diurnal rhythms to optimize the drug effect.NEW & NOTEWORTHY Sex influences cardiovascular disease, and the timing of onset of acute cardiovascular events exhibits circadian rhythms. Kidney function also exhibits sex differences and circadian rhythms. How do the natriuretic and diuretic effects of diuretics, a common treatment for hypertension that targets the kidneys, differ between the sexes? And how do these effects vary during the day? To answer these questions, we conducted computer simulations to assess the effects of loop, thiazide, and K+-sparing diuretics.

Research on the Development of WeChat Channels under the Background of Short Video

The improvement of 5G network speed has laid the foundation for the generation of short video platforms. With the help of big data, short videos can be more accurate to push the content of interest to customers. As a veteran Chinese Internet giant Tencent, in order to cater to today's fast-rising short video market, Tencent launched "WeChat Channels" to participate in the competition in the short video market. In just two years, the latest data shows that Tencent's WeChat Channel has been able to compete with Tiktok and Kwai. The authors have studied and discussed why the Tencent WeChat Channels can grow so fast in such a short period of time, and what are the implications for those who want to join the industry later. The authors analyze the business model of Wechat Channels through the network effect of short video platforms and positive feedback loops, use SWOT to analyze the competitiveness of WeChat Channels, and analyze the differentiation strategies. Through research, the authors found that the WeChat Channels itself is in the powerful online communication platform "WeChat" ecology, and the natural customer acquisition channel enables the Wechat Channels to quickly complete the original accumulation of basic customers in the early stage, and the unique push mechanism within the circle of friends allows Video account customer stickiness and higher video quality. Therefore, these two important factors have led to the result that the video account has gradually formed its own closed-loop live broadcast business.

Modeling, Stability, and Design of the Single-Phase SOGI-Based Phase-Locked Loop Considering the Frequency Feedback Loop Effect

For single-phase grid-connected inverters, the second-order generalized integrator-based phase-locked loop (SOGI-PLL) is widely used for good harmonics attenuation and frequency adaptability. However, existing studies usually neglect the frequency feedback loop in the modeling and design process, and thus, the potential instability caused by the frequency feedback loop is not well explained. Besides, the improper design of SOGI-PLL can lead to the inverter instability both under ideal and weak grid conditions. Therefore, by fully considering the coupling of the frequency feedback loop, this article establishes an accurate model for SOGI-PLL. Furthermore, effects of different PLL parameters on behaviors of both the SOGI-PLL itself and the inverter are studied, based on which a graphical method for PLL parameters design is proposed. As proved, the frequency feedback loop can deteriorate the stability and performance of both SOGI-PLL itself and inverter system, especially if rapid transient is expected. The modeling method is also extended to the low-pass filter-SOGI-PLL and the improved parameters design is discussed. Experimental results verify the correctness of the proposed PLL model and the abovementioned analysis results. The proposed model is helpful to deeply reveal the instability mechanism and provides a reference for the PLL design under nonideal grid conditions.

Effect of metakaolin utilization ratio and loop method-pre-shearing process variation on rheological properties of cementitious systems having different C3A content

Thixotropic behavior, which directly affects the fresh state properties of cementitious systems such as pumpability, compressibility and hydrostatic mold pressure, is determined by applying the loop method, step change and constant shear rate. This behavior is seriously affected by parameters such as the type, amount and fineness of the binder and the process applied in rheological measurements. In this study, the effect of cement C3A content, metakaolin utilization ratio, resting time of the mixture, pre-shear rate and applying pre-shear rate on the thixotropic behavior of the mixtures at the beginning and 20th-minutes were investigated. For this purpose, 4 types of cement having different C3A contents (2.13%, 3.60%, 6.82% and 9.05%) were used. By testing each of the 4 cements (2.13%, 3.60%, 6.82% and 9.05%) for 5 conditions (no metakaolin, 3%, 6%, 9% and 12% metakaolin), a total of 20 mixtures were prepared. For each cement type, 0, 3, 6, 9 and 12% of the total binder volume was replaced with metakaolin. The loop method was used to determine the rheological parameters. According to the results, irrespective of all parameters examined, the structural build-up area values were higher than the structural breakdown ones in the mixtures and the structure formation that occurred after 20 min was mostly reversible. It was determined that rheological parameters, structural build-up area value and rate of reversible structure formation increased with the increase in cement C3A content and metakaolin utilization rate. The increase in the initial dynamic yield stress values of the mixtures with the increase of the cement C3A ratio was more pronounced in the case where the measurement is made without waiting immediately after the pre-shear application. The effect of C3A content on dynamic yield stress and viscosity values was more pronounced with an increasing pre-shear rate. The opposite was observed for the structural build-up area values.

Impacts of vermicompost application on crop yield, ammonia volatilization and greenhouse gases emission on upland in Southwest China

Ammonia (NH3) volatilization and greenhouse gas (GHG) emission are important environment pollution sources in upland agro-ecosystems. Vermicompost was used for amending purple soil and comparing NH3 and GHG emissions. A field experiment was conducted with a comparison of organic and inorganic fertilizers in a wheat–maize rotation system in the Sichuan Basin, China. The five treatments were conventional inorganic fertilizers, NPK as control; vermicompost prepared with cow dung (VCM); and pig manure (VPM); cow dung and pig manure vermicompost, respectively (VCMNPK, VPMNPK). Total nitrogen rates of all treatments were the same. Soil NH3 volatilization and GHG emissions were monitored with the static chamber method. The results showed that NH3 volatilization occurred in the first two weeks following nitrogen (N) fertilization. The cumulative fluxes of NH3 recorded in the NPK, VCM, VPM, VCMNPK, and VPMNPK treatments were 15.4, 5.7, 6.3, 10.32, and 10.29 kg N ha−1 yr−1, respectively, in the winter and 4.8, 5.5, 19.83, 12.8, and 11.9 kg N ha−1 yr−1 respectively, in the summer. The global warming potential (GWP) 773.6 and 803.9 g CO2-eq m−2 in VCM and VPM, respectively, during the wheat season 540.6 and 576.2 g CO2-eq m−2, respectively, during the maize season. The GWPs in NPK treatment were 1032.4 and 570.7 g CO2-eq m−2 during the wheat and maize seasons, respectively. The increasing effects of nutrient loops, particularly 18 % soil total nitrogen (TN) and 31 % soil organic carbon (SOC) in VCM, and crop productivity of vermicompost treatments during the wheat–maize rotation had been evaluated. This study recommends that VCM can be considered as a better organic amendment, promoting plant growth while decreasing the environmental costs of gas emissions.

Impact of looping on premalignant polyp detection during colonoscopy

The presence of premalignant polyps on colonoscopy is an indicator of metachronous colorectal cancer. Looping during colonoscopy is associated with old age, female sex, and colonoscopy insertion time. However, the clinical significance of looping is not fully understood. We aimed to clarify the effect of looping on colorectal premalignant polyp detection. To assess the effects of looping on premalignant polyp detection using logistic regression analyses. We retrospectively investigated patients who underwent colonoscopy at Toyoshima Endoscopy Clinic between May, 2017 and October, 2020. From the clinic's endoscopy database, we extracted data on patient age, sex, endoscopist-assessed looping, colonoscopy duration, endoscopist experience, detection rate, and number of premalignant polyps. We assessed 12259 patients (mean age, 53.6 years; men, 50.7%). Looping occurred in 54.3% of the patients. Mild and severe looping were noted in 4399 and 2253 patients, respectively. The detection rates of adenomas, advanced adenomas, high-risk adenomas, clinically significant serrated polyps (CSSPs), and sessile serrated lesions (SSLs) were 44.7%, 2.0%, 9.9%, 8.9% and 3.5%, respectively. The mean numbers of adenomas and SSLs were 0.82 and 0.04, respectively. The detection rates of adenomas, high-risk adenomas, and CSSPs increased with looping severity (all P < 0.001). The number of adenomas increased with looping severity (P < 0.001). Multivariate analyses found that detection of adenomas, high-risk adenomas, and CSSPs was associated with severe looping (P < 0.001, P < 0.001, and P = 0.007, respectively) regardless of age, sex, time required for colonoscope insertion and withdrawal, and endoscopist experience. Looping severity was independently associated with high detection rates of premalignant polyps. Therefore, looping may predict the risk of metachronous colorectal cancer. Endoscopists should carefully examine the colorectum of patients with looping.

Reactivity as a tool in emancipatory activist research

Reactivity is usually seen as a problem in the human sciences. In this paper I argue that in emancipatory activist research, reactivity can be an important tool. I discuss one example: the aim of mental decolonisation in indigenous activist research. I argue that mental decolonisation can be understood as the act of replacing harmful looping effects with new, emancipatory ones.