scholarly journals A Unified Moisture Mode Framework for Seasonality of the Madden–Julian Oscillation

2018 ◽  
Vol 31 (11) ◽  
pp. 4215-4224 ◽  
Author(s):  
Xianan Jiang ◽  
Ángel F. Adames ◽  
Ming Zhao ◽  
Duane Waliser ◽  
Eric Maloney
Keyword(s):  
Close Association ◽  
Critical Role ◽  
Boreal Winter ◽  
Madden Julian Oscillation ◽  
Equatorial Wave ◽  
Moisture Mode ◽  
Northward Propagation ◽  
The Mean ◽  
Moisture Pattern

The Madden–Julian oscillation (MJO) exhibits pronounced seasonality. While it is largely characterized by equatorially eastward propagation during the boreal winter, MJO convection undergoes marked poleward movement over the Asian monsoon region during summer, producing a significant modulation of monsoon rainfall. In classical MJO theories that seek to interpret the distinct seasonality in MJO propagation features, the role of equatorial wave dynamics has been emphasized for its eastward propagation, whereas coupling between MJO convection and the mean monsoon flow is considered essential for its northward propagation. In this study, a unified physical framework based on the moisture mode theory, is offered to explain the seasonality in MJO propagation. Moistening and drying caused by horizontal advection of the lower-tropospheric mean moisture by MJO winds, which was recently found to be critical for the eastward propagation of the winter MJO, is also shown to play a dominant role in operating the northward propagation of the summer MJO. The seasonal variations in the mean moisture pattern largely shape the distinct MJO propagation in different seasons. The critical role of the seasonally varying climatological distribution of moisture for the MJO propagation is further supported by the close association between model skill in representing the MJO propagation and skill at producing the lower-tropospheric mean moisture pattern. This study thus pinpoints an important direction for climate model development for improved MJO representation during all seasons.

scholarly journals Role of Maritime Continent Land Convection on the Mean State and MJO Propagation

2020 ◽  
Vol 33 (5) ◽  
pp. 1659-1675 ◽  
Author(s):  
Min-Seop Ahn ◽  
Daehyun Kim ◽  
Yoo-Geun Ham ◽  
Sungsu Park
Keyword(s):  
Climate Model ◽  
Global Climate ◽  
Global Climate Model ◽  
Critical Role ◽  
Moisture Gradient ◽  
Moisture Distribution ◽  
Boreal Winter ◽  
Maritime Continent ◽  
The Mean

AbstractThe Maritime Continent (MC) region is known as a “barrier” in the life cycle of the Madden–Julian oscillation (MJO). During boreal winter, the MJO detours the equatorial MC land region southward and propagates through the oceanic region. Also, about half of the MJO events that initiate over the Indian Ocean cease around the MC. The mechanism through which the MC affects MJO propagation, however, has remained unanswered. The current study investigates the MJO–MC interaction with a particular focus on the role of MC land convection. Using a global climate model that simulates both mean climate and MJO realistically, we performed two sensitivity experiments in which updraft plume radius is set to its maximum and minimum value only in the MC land grid points, making convective top deeper and shallower, respectively. Our results show that MC land convection plays a key role in shaping the 3D climatological moisture distribution around the MC through its local and nonlocal effects. Shallower and weaker MC land convection results in a steepening of the vertical and meridional mean moisture gradient over the MC region. The opposite is the case when MC land convection becomes deeper and stronger. The MJO’s eastward propagation is enhanced (suppressed) with the steeper (lower) mean moisture gradient. The moist static energy (MSE) budget of the MJO reveals the vertical and meridional advection of the mean MSE by MJO wind anomalies as the key processes that are responsible for the changes in MJO propagation characteristics. Our results pinpoint the critical role of the background moisture gradient on MJO propagation.

Assessing the role of air-sea coupling in predicting Madden-Julian Oscillation with an atmosphere-ocean coupled model

2021 ◽  
pp. 1-58
Author(s):  
Jiye Wu ◽  
Yue Li ◽  
Jing-Jia Luo ◽  
Xianan Jiang
Keyword(s):  
General Circulation ◽  
Global Climate ◽  
Critical Role ◽  
Circulation Model ◽  
General Circulation Models ◽  
Asymmetric Structure ◽  
Boreal Winter ◽  
Madden Julian Oscillation ◽  
Weather Extremes

AbstractThe Madden-Julian Oscillation (MJO) provides an important source of sub-seasonal to seasonal (S2S) predictability. Improved MJO prediction can be beneficial to S2S prediction of global climate and associated weather extremes. In this study, hindcasts based on an atmosphere-ocean coupled general circulation model (CGCM) are compared to those based on atmosphere general circulation models (AGCMs) to investigate influences of air-sea interactions on MJO prediction. Our results suggest that MJO prediction skill can be extended about one week longer in the CGCM hindcasts than AGCM-only experiments, particularly for boreal winter predictions.Further analysis suggests that improved MJO prediction in the CGCM is closely associated with improved representation of moistening processes. Compared to the AGCM experiments, the CGCM better predicts the boundary-layer moisture preconditioning to the east of MJO convection, which is generally considered crucial for triggering MJO deep convection. Meanwhile, the widely extended east-west asymmetric structure in free-tropospheric moisture tendency anomalies relative to the MJO convection center as seen in the observations is also well predicted in the CGCM. Improved prediction of MJO moisture processes in CGCM is closely associated with better representation of the zonal scale of MJO circulation and stronger Kelvin waves to the east of MJO convection, both of which have been recently suggested conductive for MJO eastward propagation. The above improvements by including air-sea coupling could be largely attributed to the realistic MJO-induced SST fluctuations through the convection-SST feedback. This study confirms a critical role of atmosphere-ocean coupling for the improvement of MJO prediction.

scholarly journals Mammary gland adipocytes in lactation cycle, obesity and breast cancer

2021 ◽  
Author(s):  
Georgia Colleluori ◽  
Jessica Perugini ◽  
Giorgio Barbatelli ◽  
Saverio Cinti
Keyword(s):  
Breast Cancer ◽  
Mammary Gland ◽  
Epithelial Cells ◽  
Close Association ◽  
Critical Role ◽  
Exocrine Gland ◽  
Plastic Properties ◽  
Lactation Cycle ◽  
Gland Development

AbstractThe mammary gland (MG) is an exocrine gland present in female mammals responsible for the production and secretion of milk during the process of lactation. It is mainly composed by epithelial cells and adipocytes. Among the features that make the MG unique there are 1) its highly plastic properties displayed during pregnancy, lactation and involution (all steps belonging to the lactation cycle) and 2) its requirement to grow in close association with adipocytes which are absolutely necessary to ensure MG’s proper development at puberty and remodeling during the lactation cycle. Although MG adipocytes play such a critical role for the gland development, most of the studies have focused on its epithelial component only, leaving the role of the neighboring adipocytes largely unexplored. In this review we aim to describe evidences regarding MG’s adipocytes role and properties in physiologic conditions (gland development and lactation cycle), obesity and breast cancer, emphasizing the existing gaps in the literature which deserve further investigation.

scholarly journals Zinc deficiency may play a crucial role in dialysis-associated bacterial infections

2020 ◽  
Vol 11 (1) ◽  
pp. e9-e9
Author(s):  
Zahra Lotfi ◽  
Abbas Ali Zeraati ◽  
Elaheh Dashti ◽  
Tina Zeraati ◽  
Maryam Arghiany ◽  
...  
Keyword(s):  
Zinc Deficiency ◽  
Bacterial Infections ◽  
Critical Role ◽  
Serum Zinc ◽  
Zinc Level ◽  
Healthy Individuals ◽  
Mortality And Morbidity ◽  
Increased Risk ◽  
The Mean

Introduction: Systemic bacterial infections are a common cause of mortality and morbidity in hemodialysis patients. Zinc has a critical role in several immune system functions. Patients who have enough amounts of zinc are able to better face infections caused by various pathogens in comparison to those with zinc insufficiency Objective We sought to assess the role of zinc deficiency in dialysis-associated bacterial infections. Patients and Methods: Eighty-Three adult patients with end-stage renal disease (ESRD) on hemodialysis including 43 patients with bacterial infectious complications and 40 non-infected patients as well as 41 healthy individuals were enrolled. Clinical data, laboratory values including serum zinc level and imaging findings were collected. SPSS was utilized to analyze the data with a significance cutoff set at P < 0.05. Results: Out of 124 participants, 80 (64.51%) were males and 44 (35.49%) were females. The mean age of infected hemodialysis group, non-infected hemodialysis group, and healthy controls were 50.8 ± 16.25, 49.1 ± 18.1, and 56.3 ± 18.2 years, respectively. Catheter site infection (37.3%) and urinary tract infection (30.2%) were the most common infections. The mean serum zinc concentration was significantly lower in the infected patients, compared to non-infected patients and healthy individuals (P < 0.001). Conclusion: The ESRD patients on hemodialysis have lower serum zinc levels which are associated with increased risk of bacterial infection. The role of screening for zinc deficiency and use of supplemental zinc in these patients need to be studied.

Measurement and Prediction of Sound Exposure Levels by University Wind Bands

2010 ◽  
Vol 25 (1) ◽  
pp. 29-34 ◽  
Author(s):  
Kris Chesky
Keyword(s):  
Linear Regression Analysis ◽  
Critical Role ◽  
Significant Proportion ◽  
Sound Exposure ◽  
Sound Levels ◽  
Wind Bands ◽  
Exposure Levels ◽  
The Mean ◽  
Over Time

The purpose of this study was to determine sound exposure levels generated in two college wind bands. Dosimeter data from a large sample of ensemble-based instructional activities (n = 43) was collected over time and processed to assess associations with predictor variables that may be relevant to this context, including indicators of time spend at various intensity levels, maximum and peak sound levels, degree of variability of sound levels over time, and the percentage of time playing music. The mean dose per event for the entire sample was 109.5% and ranged from 53.8% to 166.9%. Results of linear regression analysis revealed that regressors accounted for a significant proportion of the variance in dose (F = 128.42, p < 0.000) and a statistically significant and very large (96% variance accounted for) contribution to the prediction of dose. Findings implicate the critical role of the instructor and teaching pedagogy.

scholarly journals Long-Term Infliximab Treatment in Psoriasis Patients: A National Multicentre Retrospective Study

2020 ◽  
Vol 2020 ◽  
pp. 1-3
Author(s):  
Clémentine Carlet ◽  
Damien Bichard ◽  
Marie Aleth Richard ◽  
Emmanuel Mahé ◽  
Clémence Saillard ◽  
...  
Keyword(s):  
Retrospective Study ◽  
Critical Role ◽  
Real Life ◽  
Solid Cancer ◽  
Infliximab Treatment ◽  
Efficacy And Safety ◽  
Drug Survival ◽  
The Mean

Background. Although infliximab (IFX) has been available since 2005, there are very little data on the long-term drug survival of infliximab in real-life. Objective. Our aim was to identify and describe psoriasis patients treated with IFX for longer than 6 years. Methods. Psoriasis patients treated with IFX for longer than 6 years were retrospectively included. Demographic and clinical data were collected in May 2018. Results. Between January 2005 and December 2012, 43 patients were maintained on IFX for 6 years or longer. IFX was introduced as a 4.5 line of systemic therapy. The mean duration of IFX treatment was 8.5 years (6–12). In May 2018, 30 patients (70%) were still maintained on IFX at 4–6 mg/kg every 8–10 weeks with an efficiency of about 100%. IFX was stopped in 13 patients (30%) mainly for loss of efficacy in 6 patients (46%). Three patients developed solid cancer including bladder cancer, lung cancer, and prostate cancer. Limitation. Retrospective study. Conclusion. We report the efficacy and safety of IFX maintained for up to 12 years in psoriasis patients. The long-term use of IFX was associated with a high BMI confirming the critical role of weight-based dosing for this drug.

A Further Study of ENSO Rectification: Results from an OGCM with a Seasonal Cycle*

2015 ◽  
Vol 28 (4) ◽  
pp. 1362-1382 ◽  
Author(s):  
Lijuan Hua ◽  
Yongqiang Yu ◽  
De-Zheng Sun
Keyword(s):  
Wind Stress ◽  
Seasonal Cycle ◽  
Critical Role ◽  
Warm Pool ◽  
Rectification Effect ◽  
Climate Anomalies ◽  
Eastern Equatorial Pacific ◽  
The Mean ◽  
The Impact

Abstract The potential role that rectification of ENSO plays as a viable mechanism to generate climate anomalies on the decadal and longer time scales demands a thorough study of this process. In this paper, rectification of ENSO was studied using an ocean GCM that has a realistic seasonal cycle. In addition to conducting a pair of forced ocean GCM experiments with and without ENSO fluctuations, as done in a previous study, a forced experiment was also conducted with the sign of wind anomalies reversed, with the goal of clarifying the role of the asymmetry in the wind forcing and more generally to better understand the nonlinear dynamics responsible for the rectification. It is found that the rectification effect of ENSO is to cool the western Pacific warm pool and warm the eastern equatorial Pacific. Further, it is found that when the sign of the wind stress anomalies is reversed the impact of the rectification on the mean state remains almost unchanged. This lack of change is further explained by noting that the upper-ocean temperature and velocity anomalies (T′, u′, υ′, and w′) are found to respond to the wind stress anomalies linearly, except for the strongest El Niño years. Thus, the correlation between T′ and (u′, υ′, w′) [and thus the nonlinear dynamical heating (NDH)] remains the same when the sign of the wind stress anomalies is reversed. Indeed, the spatial patterns of NDH in all four seasons are found to resemble the rectified effect of ENSO in the mean temperature field in the respective seasons, indicating the critical role of NDH in the rectification.

scholarly journals Twenty-four-hour blood pressure variability plays a detrimental role in the neurological outcome of hemorrhagic stroke

2018 ◽  
Vol 46 (7) ◽  
pp. 2558-2568 ◽  
Author(s):  
Huan-Xin Zhang ◽  
Qun-Xiong Fan ◽  
Shi-Zhen Xue ◽  
Min Zhang ◽  
Ji-Xian Zhao
Keyword(s):  
Blood Pressure ◽  
Neurological Outcome ◽  
Blood Pressure Variability ◽  
Hemorrhagic Stroke ◽  
Critical Role ◽  
National Institutes Of Health ◽  
Neurological Prognosis ◽  
The Mean ◽  
Maximum Minimum

Background Blood pressure variability (BPV) is a modifiable risk factor for stroke. This study was performed to determine the prognostic role of BPV in patients with acute hemorrhagic stroke. Methods The data of 131 hospitalized hypertensive patients with spontaneous intracerebral hemorrhage (sICH) were collected. All patients underwent examinations using several neurological scales (Glasgow Coma Scale, National Institutes of Health Stroke Scale, and modified Rankin scale [mRS]) and BP measurements at different time points. Results Sex, age, hematoma volume, and neurological scores were not significantly different between patients with a favorable and unfavorable prognosis for sICH. However, significant differences were found in hypertension, diabetes, metabolic syndrome, atrial fibrillation, smoking, and stroke history. The standard deviation (SD), coefficient of variation (CV), and maximum–minimum range (Max–Min) of diastolic BP and the mean, SD, CV, and Max–Min of systolic BP significantly differed between the groups. Statistical analysis also demonstrated correlations between the 90-day mRS score and BPV and between systolic BPV and the 90-day mRS score. Conclusion High systolic or diastolic BPV within 24 hours of hemorrhagic stroke onset is associated with the 90-day neurological prognosis. The 24-hour BPV plays a critical role in the neurological outcome of hemorrhagic stroke.

scholarly journals The Basally Expressed p53-Mediated Homeostatic Function

2021 ◽  
Vol 9 ◽  
Author(s):  
Isha Nagpal ◽  
Zhi-Min Yuan
Keyword(s):  
Animal Studies ◽  
Close Association ◽  
P53 Protein ◽  
Critical Role ◽  
Protein Levels ◽  
Elevated Expression ◽  
Homeostatic Function ◽  
E6 Protein ◽  
Insight Into

Apart from mutations in the p53 gene, p53 functions can be alternatively compromised by a decrease in nuclear p53 protein levels or activities. In accordance, enhanced p53 protein turnover due to elevated expression of the critical p53 E3 ligase MDM2 or MDM2/MDMX is found in many human cancers. Likewise, the HPV viral E6 protein-mediated p53 degradation critically contributes to the tumorigenesis of cervical cancer. In addition, growth-promoting signaling-induced cell proliferation is accompanied by p53 downregulation. Animal studies have also shown that loss of p53 is essential for oncogenes to drive malignant transformation. The close association between p53 downregulation and carcinogenesis implicates a critical role of basally expressed p53. In accordance, available evidence indicates that a reduced level of basal p53 is usually associated with disruption of homeostasis, suggesting a homeostatic function mediated by basal p53. However, basally expressed p53 under non-stress conditions is maintained at a relatively low abundance with little transcriptional activity, raising the question of how basal p53 could protect homeostasis. In this review, we summarize the findings pertinent to basal p53-mediated activities in the hope of developing a model in which basally expressed p53 functions as a barrier to anabolic metabolism to preserve homeostasis. Future investigation is necessary to characterize basal p53 functionally and to obtain an improved understanding of p53 homeostatic function, which would offer novel insight into the role of p53 in tumor suppression.

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