scholarly journals Influence of the choice of insolation forcing on the results of a conceptual glacial cycle model

2021 ◽  
Author(s):  
Gaëlle Leloup ◽  
Didier Paillard
Keyword(s):  
Frequency Shift ◽  
Model Data ◽  
Glacial Cycle ◽  
Cycle Model ◽  
Ice Volume ◽  
Summer Insolation ◽  
Time Period ◽  
Insolation Forcing ◽  
Over Time

Abstract. Over the Quaternary, the ice volume variations are “paced” by the astronomy. However, the precise way in which the astronomical parameters influence the glacial-interglacial cycles is not clear. The origin of the 100 kyr cycles over the last million year and of the switch from 40 kyr to 100 kyr cycles over the Mid Pleistocene Transition remain largely unexplained. By representing the climate system as oscillating between two states, glaciation and deglaciation, switching once a glaciation and a deglaciation thresholds are crossed, the main features of the ice volume record can be reproduced (Parrenin and Paillard, 2012). However, previous studies have only focused on the use of a single summer insolation as input. Here, we use a simple conceptual model to test and discuss the influence of the use of different summer insolation forcings, having different contributions from precession and obliquity, on the model results. We show that some features are robust. Specifically, to be able to reproduce the frequency shift over the Mid Pleistocene Transition, the deglaciation threshold needs to increase over time, independently of the summer insolation used as input. The quality of the model data agreement however depends on the chosen type of summer insolation and time period considered.

scholarly journals Ice-driven CO<sub>2</sub> feedback on ice volume

2006 ◽  
Vol 2 (1) ◽  
pp. 43-55 ◽  
Author(s):  
W. F. Ruddiman
Keyword(s):  
Geographic Origin ◽  
Ice Sheets ◽  
Ice Sheet ◽  
Early Pleistocene ◽  
Schematic Model ◽  
Co2 Response ◽  
Ice Volume ◽  
Summer Insolation ◽  
Northern Summer ◽  
Insolation Forcing

Abstract. The origin of the major ice-sheet variations during the last 2.7 million years is a long-standing mystery. Neither the dominant 41 000-year cycles in δ18O/ice-volume during the late Pliocene and early Pleistocene nor the late-Pleistocene oscillations near 100 000 years is a linear ("Milankovitch") response to summer insolation forcing. Both responses must result from non-linear behavior within the climate system. Greenhouse gases (primarily CO2) are a plausible source of the required non-linearity, but confusion has persisted over whether the gases force ice volume or are a positive feedback. During the last several hundred thousand years, CO2 and ice volume (marine δ18O) have varied in phase at the 41 000-year obliquity cycle and nearly in phase within the ~100 000-year band. This timing rules out greenhouse-gas forcing of a very slow ice response and instead favors ice control of a fast CO2 response. In the schematic model proposed here, ice sheets responded linearly to insolation forcing at the precession and obliquity cycles prior to 0.9 million years ago, but CO2 feedback amplified the ice response at the 41 000-year period by a factor of approximately two. After 0.9 million years ago, with slow polar cooling, ablation weakened. CO2 feedback continued to amplify ice-sheet growth every 41 000 years, but weaker ablation permitted some ice to survive insolation maxima of low intensity. Step-wise growth of these longer-lived ice sheets continued until peaks in northern summer insolation produced abrupt deglaciations every ~85 000 to ~115 000 years. Most of the deglacial ice melting resulted from the same CO2/temperature feedback that had built the ice sheets. Several processes have the northern geographic origin, as well as the requisite orbital tempo and phasing, to be candidate mechanisms for ice-sheet control of CO2 and their own feedback.

Measuring the improving quality of outpatient care in medical oncology practices in the United States.

2012 ◽  
Vol 30 (34_suppl) ◽  
pp. 66-66
Author(s):  
Michael N. Neuss ◽  
Jennifer Malin ◽  
Stephanie Chan ◽  
Pamela Kadlubek ◽  
John L. Adams ◽  
...  
Keyword(s):  
Clinical Information ◽  
The United States ◽  
Time Period ◽  
Medical Oncologists ◽  
The Mean ◽  
Highly Correlated ◽  
American Society ◽  
Oncology Practice ◽  
Over Time

66 Background: The American Society of Clinical Oncology (ASCO) Quality Oncology Practice Initiative (QOPI) has provided a method for measurement of process based practice quality since 2006. We sought to determine whether QOPI participants show improvement in measured quality over time, and if change is demonstrated, those factors in either the measures or participants which are associated with change. Methods: 156 participant medical practice groups, which did not submit trainee data, participated in at least two collection rounds from 2006 through 2010, and reported on ≥30 patients per round from were included in analysis from a larger group of 306 participants from this time period. A database of these reports was used to evaluate trends in scoring among participants. A linear regression model, which controlled for varied initial performance, was used to estimate the effect of participation over time and evaluate participant and measure characteristics. Measures were aggregated into categories to evaluate which factors correlated with change. Results: Participants completed a mean of 5.71 (S.D. 1.84) rounds of data collection. Adjusted mean quality scores improved from 0.71 (95% C.I. 0.42 – 0.91) to 0.85 (95% C.I. 0.60 – 0.95). Overall odds ratio of improvement over time was 1.09 (p < 0.0001). The greatest improvement was seen in measures assessing newly introduced clinical information, where the mean scores improved from 0.05 (95% C.I. 0.01 – 0.17) to 0.69 (95% C.I. 0.33 – 0.91), (p ≤ 0.0001). Many measures showed no change over time. Conclusions: QOPI has gained widespread adoption and approximately 15% of U.S. medical oncologists participate. Participation over time is highly correlated with improvement in measured performance. Much of this improvement is the result of the adoption of newly introduced clinical information. Some measures show no change despite significant opportunity for improvement.

scholarly journals National Trends in Utilization and 1-Year Outcomes with Transplantation of HCV-Viremic Kidneys

2019 ◽  
Vol 30 (10) ◽  
pp. 1939-1951 ◽  
Author(s):  
Vishnu S. Potluri ◽  
David S. Goldberg ◽  
Sumit Mohan ◽  
Roy D. Bloom ◽  
Deirdre Sawinski ◽  
...  
Keyword(s):  
Kidney Donor ◽  
Short Term ◽  
Time Period ◽  
Pilot Trials ◽  
Allograft Function ◽  
Organ Quality ◽  
Transplant Candidates ◽  
National Trends ◽  
Over Time

BackgroundRecent pilot trials have demonstrated the safety of transplanting HCV-viremic kidneys into HCV-seronegative recipients. However, it remains unclear if allograft function is impacted by donor HCV-viremia or recipient HCV-serostatus.MethodsWe used national United States registry data to examine trends in HCV-viremic kidney use between 4/1/2015 and 3/31/2019. We applied advanced matching methods to compare eGFR for similar kidneys transplanted into highly similar recipients of kidney transplants.ResultsOver time, HCV-seronegative recipients received a rising proportion of HCV-viremic kidneys. During the first quarter of 2019, 200 HCV-viremic kidneys were transplanted into HCV-seronegative recipients, versus 69 into HCV-seropositive recipients, while 105 HCV-viremic kidneys were discarded. The probability of HCV-viremic kidney discard has declined over time. Kidney transplant candidates willing to accept a HCV-seropositive kidney increased from 2936 to 16,809 from during this time period. When transplanted into HCV-seronegative recipients, HCV-viremic kidneys matched to HCV-non-viremic kidneys on predictors of organ quality, except HCV, had similar 1-year eGFR (66.3 versus 67.1 ml/min per 1.73 m2, P=0.86). This was despite the much worse kidney donor profile index scores assigned to the HCV-viremic kidneys. Recipient HCV-serostatus was not associated with a clinically meaningful difference in 1-year eGFR (66.5 versus 71.1 ml/min per 1.73 m2, P=0.056) after transplantation of HCV-viremic kidneys.ConclusionsBy 2019, HCV-seronegative patients received the majority of kidneys transplanted from HCV-viremic donors. Widely used organ quality scores underestimated the quality of HCV-viremic kidneys based on 1-year allograft function. Recipient HCV-serostatus was also not associated with worse short-term allograft function using HCV-viremic kidneys.

Psychological and Cognitive Aspects of Borderline Intellectual Functioning

2017 ◽  
Vol 22 (3) ◽  
pp. 159-166 ◽  
Author(s):  
Bastianina Contena ◽  
Stefano Taddei
Keyword(s):  
Quality Of Life ◽  
Systematic Review ◽  
Intellectual Functioning ◽  
Clinical Impact ◽  
Review Of The Literature ◽  
Borderline Intellectual Functioning ◽  
General Quality ◽  
Meta Analyses ◽  
Over Time

Abstract. Borderline Intellectual Functioning (BIF) refers to a global IQ ranging from 71 to 84, and it represents a condition of clinical attention for its association with other disorders and its influence on the outcomes of treatments and, in general, quality of life and adaptation. Furthermore, its definition has changed over time causing a relevant clinical impact. For this reason, a systematic review of the literature on this topic can promote an understanding of what has been studied, and can differentiate what is currently attributable to BIF from that which cannot be associated with this kind of intellectual functioning. Using Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) criteria, we have conducted a review of the literature about BIF. The results suggest that this condition is still associated with mental retardation, and only a few studies have focused specifically on this condition.

The reciprocity of the quality of care providers' occupational life of and the quality of care: A cycle model

2013 ◽  
Author(s):  
Marco Ferrara ◽  
Sara Viotti ◽  
Daniela Converso ◽  
Valentina Trotta ◽  
Gloria Guidetti ◽  
...  
Keyword(s):  
Quality Of Care ◽  
Care Providers ◽  
Cycle Model ◽  
Occupational Life

Quality of life over time in a German cohort of breast cancer survivors

2017 ◽  
Author(s):  
K Thöne ◽  
N Obi ◽  
A Jung ◽  
M Schmidt ◽  
J Chang-Claude ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Quality Of Life ◽  
Cancer Survivors ◽  
Breast Cancer Survivors ◽  
Over Time

Effectiveness of the Chiari Health Index for Pediatrics instrument in measuring postoperative health-related quality of life in pediatric patients with Chiari malformation type I

2020 ◽  
pp. 1-6
Author(s):  
Georgina E. Sellyn ◽  
Alan R. Tang ◽  
Shilin Zhao ◽  
Madeleine Sherburn ◽  
Rachel Pellegrino ◽  
...  
Keyword(s):  
Surgical Intervention ◽  
Type I ◽  
Health Related Quality ◽  
Health Index ◽  
Chiari Malformation Type I ◽  
Related Quality ◽  
Health Related ◽  
Over Time

OBJECTIVEThe authors’ previously published work validated the Chiari Health Index for Pediatrics (CHIP), a new instrument for measuring health-related quality of life (HRQOL) for pediatric Chiari malformation type I (CM-I) patients. In this study, the authors further evaluated the CHIP to assess HRQOL changes over time and correlate changes in HRQOL to changes in symptomatology and radiological factors in CM-I patients who undergo surgical intervention. Strong HRQOL evaluation instruments are currently lacking for pediatric CM-I patients, creating the need for a standardized HRQOL instrument for this patient population. This study serves as the first analysis of the CHIP instrument’s effectiveness in measuring short-term HRQOL changes in pediatric CM-I patients and can be a useful tool in future CM-I HRQOL studies.METHODSThe authors evaluated prospectively collected CHIP scores and clinical factors of surgical intervention in patients younger than 18 years. To be included, patients completed a baseline CHIP captured during the preoperative visit, and at least 1 follow-up CHIP administered postoperatively. CHIP has 2 domains (physical and psychosocial) comprising 4 components, the 3 physical components of pain frequency, pain severity, and nonpain symptoms, and a single psychosocial component. Each CHIP category is scored on a scale, with 0 indicating absent and 1 indicating present, with higher scores indicating better HRQOL. Wilcoxon paired tests, Spearman correlations, and linear regression models were used to evaluate and correlate HRQOL, symptomatology, and radiographic factors.RESULTSSixty-three patients made up the analysis cohort (92% Caucasian, 52% female, mean age 11.8 years, average follow-up time 15.4 months). Dural augmentation was performed in 92% of patients. Of the 63 patients, 48 reported preoperative symptoms and 42 had a preoperative syrinx. From baseline, overall CHIP scores significantly improved over time (from 0.71 to 0.78, p < 0.001). Significant improvement in CHIP scores was seen in patients presenting at baseline with neck/back pain (p = 0.015) and headaches (p < 0.001) and in patients with extremity numbness trending at p = 0.064. Patients with syringomyelia were found to have improvement in CHIP scores over time (0.75 to 0.82, p < 0.001), as well as significant improvement in all 4 components. Additionally, improved CHIP scores were found to be significantly associated with age in patients with cervical (p = 0.009) or thoracic (p = 0.011) syrinxes.CONCLUSIONSThe study data show that the CHIP is an effective instrument for measuring HRQOL over time. Additionally, the CHIP was found to be significantly correlated to changes in symptomatology, a finding indicating that this instrument is a clinically valuable tool for the management of CM-I.

1,3-Thiazolidin-4-ones: Biological Potential, History, Synthetic Development and Green Methodologies

2018 ◽  
Vol 15 (8) ◽  
pp. 1109-1123
Author(s):  
Jonas da Silva Santos ◽  
Joel Jones Junior ◽  
Flavia M. da Silva
Keyword(s):  
Quality Of Life ◽  
Green Chemistry ◽  
Functional Group ◽  
Biological Properties ◽  
Structural Theory ◽  
Molecular Structures ◽  
Biological Potential ◽  
Synthetic Methodologies ◽  
Over Time

Background: We present here the synthesis of 1,3-thiazolidin-4-one (1) and its functionalised analogues, such as the classical isosteres, glitazone (1,3-thiazolidine-2,4-dione) (2), rhodanine (2-thioxo-1,3- thiazolidin-4-one) (3) and pseudothiohydantoin (2-imino-1,3-thiazolidin-4-one) (4) started in the midnineteenth century to the present day (1865-2018). Objective: The review focuses on the differences in the representation of the molecular structures discussed here over time since the first discussions about the structural theory by Kekulé, Couper and Butlerov. Moreover, advanced synthesis methodologies have been developed for obtaining these functional group, including green chemistry. We discuss about its structure and stability and we show the great biological potential. Conclusion: The 1,3-thiazolidin-4-one nucleus and functionalised analogues such as glitazones (1,3- thiazolidine-2,4-diones), rhodanines (2-thioxo-1,3-thiazolidin-4-ones) and pseudothiohydantoins (2-imino-1,3- thiazolidine-2-4-ones) have great pharmacological importance, and they are already found in commercial pharmaceuticals. Studies indicate a promising future in the area of medicinal chemistry with potential activities against different diseases. The synthesis of these nuclei started in the mid-nineteenth century (1865), with the first discussions about the structural theory by Kekulé, Couper and Butlerov. The present study has demonstrated the differences in the representations of the molecular structures discussed here over time. Since then, various synthetic methodologies have been developed for obtaining these nuclei, and several studies on their structural and biological properties have been performed. Different studies with regards to the green synthesis of these compounds were also presented here. This is the result of the process of environmental awareness. Additionally, the planet Earth is already showing clear signs of depletion, which is currently decreasing the quality of life.

Biopsychosocial Patterning of Multimorbidity and Its Consequences

2018 ◽  
pp. 220-236
Author(s):  
Elliot Friedman ◽  
Beth LeBreton ◽  
Lindsay Fuzzell ◽  
Elizabeth Wehrpsann
Keyword(s):  
Quality Of Life ◽  
Older Adults ◽  
Functional Outcomes ◽  
The United States ◽  
Chronic Medical Conditions ◽  
Quality Of Life Research ◽  
Increased Risk ◽  
Over Time

By many estimates the majority of adults over age 65 have two or more chronic medical conditions (multimorbidity) and are consequently at increased risk of adverse functional outcomes. Nonetheless, many older adults with multimorbidity are able to maintain high levels of function and retain good quality of life. Research presented here is designed to understand the influences that help ensure better functional outcomes in these older adults. This chapter presents findings that draw on data from the Midlife in the United States study. The independent and interactive contributions of diverse factors to multimorbidity and changes in multimorbidity over time are reviewed. The degree that multimorbidity increases risk of cognitive impairment and disability is examined. The role of inflammation as a mediator is considered. Multimorbidity is increasingly the norm for older adults, so better understanding of factors contributing to variability in multimorbidity-related outcomes can lead to improved quality of life.

scholarly journals P139 What impact does JIA have on health-related quality of life over time and by gender?

Rheumatology ◽  
2020 ◽  
Vol 59 (Supplement_2) ◽  
Author(s):  
Andrew Smith ◽  
Bishma Saqib ◽  
Rebecca Lee ◽  
Wendy Thomson ◽  
Lis Cordingley
Keyword(s):  
Quality Of Life ◽  
Health Status ◽  
Child Health ◽  
Reference Population ◽  
Health Related Quality ◽  
Related Quality ◽  
Health Related ◽  
Over Time ◽  
Domain Scores

Abstract Background Juvenile idiopathic arthritis (JIA) is a heterogeneous group of arthritic conditions presenting in children and young people, in which physical limitations and associated complications can have detrimental effects on physical and psychosocial wellbeing. This study aims to investigate the impact of living with JIA on different aspects of health-related quality of life (HRQoL) and to explore how this changes over time, using data from the Childhood Arthritis Prospective Study (CAPS). Methods Longitudinal data collected as part of CAPS were analysed. HRQoL was assessed at baseline, 1 year and 3 years’ post-diagnosis using the Child Health Questionnaire (CHQ), a parent-completed form for children from 5 years of age. The CHQ measures physical, emotional and social components of child health status. Raw domain scores were transformed via algorithm into values ranging from 0-100, with higher scores indicating better health status. Mean (standard deviation) and median (interquartile range) for each domain were determined, both for the full cohort and by gender. Differences between median scores at baseline and 3 years were assessed using the Wilcoxon signed-rank test. Mean scores of each domain were visually compared with a reference population sample of healthy children from the United States. Results 184 participants completed the questionnaire at all 3 time points. At baseline, compared to the reference population, children with JIA scored lower in every domain although scores were closer between the 2 groups at 3 years. Median scores improved over time, the exception being the general health perceptions domain which decreased after baseline. Domains with the greatest improvement were physical functioning,“bodily pain and social-physical. The largest changes occurred from baseline to 1 year. Statistically significant differences between baseline and 3-year scores were found for all domains. Domain scores for male and female participants were very similar at baseline, though scores for male participants indicated slightly better health at 1 and 3 years for both physical and psychosocial domains. Conclusion JIA has significant impact on HRQoL, which improves within 3 years of diagnosis with the greatest improvement occurring within the first year. Physical health domains show greater improvement over time than psychosocial domains, although psychosocial scores were generally higher throughout the study. Male participants tend to score slightly higher than female participants in both physical and psychosocial domains after baseline. Further research should explore measurable patient, age or disease-related drivers of HRQoL. Disclosures A. Smith None. B. Saqib None. R. Lee None. W. Thomson None. L. Cordingley None.

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