scholarly journals Eddy-Induced Particle Dispersion in the Near-Surface North Atlantic

2012 ◽  
Vol 42 (12) ◽  
pp. 2206-2228 ◽  
Author(s):  
Irina I. Rypina ◽  
Igor Kamenkovich ◽  
Pavel Berloff ◽  
Lawrence J. Pratt
Keyword(s):  
North Atlantic ◽  
Particle Dispersion ◽  
Material Transport ◽  
Near Surface ◽  
The Mean ◽  
Surface Drifters ◽  
Particle Spreading ◽  
One Year ◽  
Ekman Advection

Abstract This study investigates the anisotropic properties of the eddy-induced material transport in the near-surface North Atlantic from two independent datasets, one simulated from the sea surface height altimetry and one derived from real-ocean surface drifters, and systematically examines the interactions between the mean- and eddy-induced material transport in the region. The Lagrangian particle dispersion, which is widely used to characterize the eddy-induced tracer fluxes, is quantified by constructing the “spreading ellipses.” The analysis consistently demonstrates that this dispersion is spatially inhomogeneous and strongly anisotropic. The spreading is larger and more anisotropic in the subtropical than in the subpolar gyre, and the largest ellipses occur in the Gulf Stream vicinity. Even at times longer than half a year, the spreading exhibits significant nondiffusive behavior in some parts of the domain. The eddies in this study are defined as deviations from the long-term time-mean. The contributions from the climatological annual cycle, interannual, and subannual (shorter than one year) variability are investigated, and the latter is shown to have the strongest effect on the anisotropy of particle spreading. The influence of the mean advection on the eddy-induced particle spreading is investigated using the “eddy-following-full-trajectories” technique and is found to be significant. The role of the Ekman advection is, however, secondary. The pronounced anisotropy of particle dispersion is expected to have important implications for distributing oceanic tracers, and for parameterizing eddy-induced tracer transfer in non-eddy-resolving models.

scholarly journals One-Year Visual and Refractive Outcomes following LASIK for Myopia and Myopic Astigmatism with MEL 90 versus Schwind Amaris 750S Excimer Laser: A Comparative Study

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Sheetal Brar ◽  
Dishitha P. Rathod ◽  
C. R. Roopashree ◽  
Sri Ganesh
Keyword(s):  
Comparative Study ◽  
Clinical Outcomes ◽  
Excimer Laser ◽  
Infectious Keratitis ◽  
Safety And Efficacy ◽  
Refractive Outcomes ◽  
The Mean ◽  
One Year ◽  
Myopic Astigmatism

Purpose. To compare clinical outcomes following LASIK for myopia performed with MEL 90 vs. Schwind Amaris 750S excimer laser. Methods. Data were collected retrospectively for patients who underwent Femto-LASIK, using the MEL 90 and Schwind Amaris 750S excimer laser for correction of myopia and myopic astigmatism within the range of −1.00 to −10.00 D SE from January 2013 till June 2018. Outcomes were analysed at 12 months for safety, efficacy, enhancement rate, and long-term complications. Results. A total of 328 eyes of 328 patients were analysed. One hundred and sixty-three eyes were treated with Schwind Amaris and the remaining 165 eyes with the MEL 90 laser. Twelve months postoperatively, the mean UDVA, CDVA, residual SE, and cylinder in the Amaris group were −0.10 ± 0.09 logMAR, −0.14 ± 0.06 logMAR, −0.21 ± 0.22 D, −0.13 ± 0.18 D versus −0.05 ± 0.07 logMAR, −0.09 ± 0.08 logMAR, −0.23 ± 0.23 D, and −0.14 ± 0.21 D for the MEL 90 group ( p values >0.05). For the Amaris group, safety and efficacy indices were 1.12 and 1.02, whereas for the MEL 90 group, these indices were 1.08 and 1.00, respectively. No eye in either group had any postop flap-related complications, infectious keratitis, diffuse lamellar keratitis, or keratectasia. Two eyes in the Amaris and 4 eyes in MEL 90 group required enhancement for the progression of myopia. Conclusion. At 12 months, both Schwind Amaris 750S and MEL 90 lasers demonstrated comparable clinical outcomes for myopic LASIK in a single surgeon setting.

Near-surface wind speeds in ERA5: Climatology, decadal variability and long-term trends

2021 ◽  
Author(s):  
Terhi K. Laurila ◽  
Victoria A. Sinclair ◽  
Hilppa Gregow
Keyword(s):  
Iberian Peninsula ◽  
North Atlantic ◽  
Decadal Variability ◽  
Surface Wind ◽  
Northern Europe ◽  
Near Surface ◽  
Wind Speeds ◽  
The North ◽  
The North Atlantic

<p>The knowledge of long-term climate and variability of near-surface wind speeds is essential and widely used among meteorologists, climate scientists and in industries such as wind energy and forestry. The new high-resolution ERA5 reanalysis from the European Centre for Medium-Range Weather Forecasts (ECMWF) will likely be used as a reference in future climate projections and in many wind-related applications. Hence, it is important to know what is the mean climate and variability of wind speeds in ERA5.</p><p>We present the monthly 10-m wind speed climate and decadal variability in the North Atlantic and Europe during the 40-year period (1979-2018) based on ERA5. In addition, we examine temporal time series and possible trends in three locations: the central North Atlantic, Finland and Iberian Peninsula. Moreover, we investigate what are the physical reasons for the decadal changes in 10-m wind speeds.</p><p>The 40-year mean and the 98th percentile wind speeds show a distinct contrast between land and sea with the strongest winds over the ocean and a seasonal variation with the strongest winds during winter time. The winds have the highest values and variabilities associated with storm tracks and local wind phenomena such as the mistral. To investigate the extremeness of the winds, we defined an extreme find factor (EWF) which is the ratio between the 98th percentile and mean wind speeds. The EWF is higher in southern Europe than in northern Europe during all months. Mostly no statistically significant linear trends of 10-m wind speeds were found in the 40-year period in the three locations and the annual and decadal variability was large.</p><p>The windiest decade in northern Europe was the 1990s and in southern Europe the 1980s and 2010s. The decadal changes in 10-m wind speeds were largely explained by the position of the jet stream and storm tracks and the strength of the north-south pressure gradient over the North Atlantic. In addition, we investigated the correlation between the North Atlantic Oscillation (NAO) and the Atlantic Multi-decadal Oscillation (AMO) in the three locations. The NAO has a positive correlation in the central North Atlantic and Finland and a negative correlation in Iberian Peninsula. The AMO correlates moderately with the winds in the central North Atlantic but no correlation was found in Finland or the Iberian Peninsula. Overall, our study highlights that rather than just using long-term linear trends in wind speeds it is more informative to consider inter-annual or decadal variability.</p>

Identifying Effectors of Outcomes in Patients with Large Umbilical Hernias

2016 ◽  
Vol 82 (7) ◽  
pp. 613-621 ◽  
Author(s):  
Steven A. Groene ◽  
Davis W. Heniford ◽  
Tanushree Prasad ◽  
Amy E. Lincourt ◽  
Vedra A. Augenstein
Keyword(s):  
Umbilical Hernia ◽  
Defect Size ◽  
Long Term Outcomes ◽  
Preoperative Pain ◽  
The Mean ◽  
The Difference ◽  
One Year

Quality of life (QOL) has become an important focus of hernia repair outcomes. This study aims to identify factors which lead to ideal outcomes (asymptomatic and without recurrence) in large umbilical hernias (defect size ≥9 cm2). Review of the prospective International Hernia Mesh Registry was performed. The Carolinas Comfort Scale was used to measure QOL at 1-, 6-, and 12-month follow-up. Demographics, operative details, complications, and QOL data were evaluated using standard statistical methods. Forty-four large umbilical hernia repairs were analyzed. Demographics included: average age 53.6 ± 12.0 and body mass index 34.9 ± 7.2 kg/m2. The mean defect size was 21.7 ± 16.9 cm2, and 72.7 per cent were performed laparoscopically. Complications included hematoma (2.3%), seroma (12.6%), and recurrence (9.1%). Follow-up and ideal outcomes were one month = 28.2 per cent, six months = 42.9 per cent, one year = 55.6 per cent. All patients who remained symptomatic at one and two years were significantly symptomatic before surgery. Symptomatic preoperative activity limitation was a significant predictor of nonideal outcomes at one year ( P = 0.02). Symptomatic preoperative pain was associated with nonideal outcomes at one year, though the difference was not statistically significant ( P = 0.06). Operative technique, mesh choice, and fixation technique did not impact recurrence or QOL. Repair of umbilical hernia with defects ≥9 cm2 had a surprising low rate of ideal outcomes (asymptomatic and no recurrence). All patients with nonideal long-term outcomes had preoperative pain and activity limitations. These data may suggest that umbilical hernia should be repaired when they are small and asymptomatic.

scholarly journals Atmospheric mercury observations from Antarctica: seasonal variation and source and sink region calculations

2012 ◽  
Vol 12 (7) ◽  
pp. 3241-3251 ◽  
Author(s):  
K. A. Pfaffhuber ◽  
T. Berg ◽  
D. Hirdman ◽  
A. Stohl
Keyword(s):  
Southern Hemisphere ◽  
Dispersion Model ◽  
Particle Dispersion ◽  
Atmospheric Mercury ◽  
The Arctic ◽  
Research Station ◽  
The Mean ◽  
The Antarctic ◽  
Source And Sink

Abstract. Long term atmospheric mercury measurements in the Southern Hemisphere are scarce and in Antarctica completely absent. Recent studies have shown that the Antarctic continent plays an important role in the global mercury cycle. Therefore, long term measurements of gaseous elemental mercury (GEM) were initiated at the Norwegian Antarctic Research Station, Troll (TRS) in order to improve our understanding of atmospheric transport, transformation and removal processes of GEM. GEM measurements started in February 2007 and are still ongoing, and this paper presents results from the first four years. The mean annual GEM concentration of 0.93 ± 0.19 ng m−3 is in good agreement with other recent southern-hemispheric measurements. Measurements of GEM were combined with the output of the Lagrangian particle dispersion model FLEXPART, for a statistical analysis of GEM source and sink regions. It was found that the ocean is a source of GEM to TRS year round, especially in summer and fall. On time scales of up to 20 days, there is little direct transport of GEM to TRS from Southern Hemisphere continents, but sources there are important for determining the overall GEM load in the Southern Hemisphere and for the mean GEM concentration at TRS. Further, the sea ice and marginal ice zones are GEM sinks in spring as also seen in the Arctic, but the Antarctic oceanic sink seems weaker. Contrary to the Arctic, a strong summer time GEM sink was found, when air originates from the Antarctic plateau, which shows that the summertime removal mechanism of GEM is completely different and is caused by other chemical processes than the springtime atmospheric mercury depletion events. The results were corroborated by an analysis of ozone source and sink regions.

Liver function tests and one year risperidone treatment in children and adolescents

2011 ◽  
Vol 26 (S2) ◽  
pp. 280-280
Author(s):  
A. Erdogan ◽  
N. Yurteri ◽  
A.E. Tufan ◽  
H. Ankarali ◽  
E. Demirci
Keyword(s):  
Liver Function ◽  
Children And Adolescents ◽  
Liver Enzymes ◽  
Antipsychotic Agent ◽  
Liver Function Tests ◽  
Function Tests ◽  
The Mean ◽  
One Year ◽  
Risperidone Treatment

ObjectiveRisperidone is an atypical antipsychotic agent, despite its many advantages and widespread use, there is increasing attention to the adverse effects associated with long-term exposure to this drug.We aimed to investigate the changes in the liver function tests (LFTs) associated with one year risperidone treatment in children and adolescents.MethodsOne hundred youths who treated with risperidone more than one year were included in the study. For this study, patients’ baseline and follow-up weight and hepatobiliary function tests including alanine aminotransferases(ALT) and aspartat aminotransferases (AST), gamma gluatamyl transerase (GGT), alkaline phosphatase (ALP) and serum bilirubin levels were measured baseline, after the treatment period of six months and one year.ResultsAsymptomatic liver function test abnormalities mostly ALP elevation was found in subjects treated with risperidone. The mean levels of liver enzymes and billuribin of the patients were significantly higher after one year of treatment than the baseline. Also the mean levels of liver enzymes and billuribin of the patients were significantly higher after one year of treatment than the six months. There was significant association between changes in weight, risperidone dose and liver enzymes and billuribin levels.ConclusionsThese findings suggest that risperidone treatment in the long term commonly leads to liver function changes however it rarely may induce a serious hepatic toxicity at therapeutic doses in children and adolescents.

The effectiveness of TBL with real patients in neurology education in terms of knowledge retention, in-class engagement, and learner reactions

2017 ◽  
Vol 41 (1) ◽  
pp. 38-43 ◽  
Author(s):  
Mustafa Kemal Alimoglu ◽  
Selda Yardım ◽  
Hilmi Uysal
Keyword(s):  
Student Satisfaction ◽  
Retention Test ◽  
Knowledge Retention ◽  
Learner Engagement ◽  
The Mean ◽  
Exam Scores ◽  
One Year ◽  
Academic Year ◽  
Real Patients

In our medical school, we changed from a lecture-based method to a team-based learning (TBL) method to teach “polyneuropathies” in the neurology clerkship starting from the 2014 to 2015 academic year. Real patients were used instead of written scenarios in TBL sessions. This study aimed to compare former lecture-based and the current TBL methods in terms of knowledge retention, in-class learner engagement, and learner reactions. First, we determined in-class engagement and satisfaction of the students for the lectures given in the 2013–2014 academic year. The following year, besides the same criteria, we also determined individual (IRAT) and group readiness test (GRAT) scores in the TBL group. End-of-clerkship exam scores for both groups were recorded. Additionally, opinions of patients about their experiences throughout the TBL process were determined. One year later (2015 for lecture and 2016 for TBL), both groups sat for an MCQ test to determine their knowledge retention levels. We found no difference between groups regarding end-of-clerkship exam scores. The mean knowledge retention test score of the TBL group was significantly higher than that of the lecture group (5.85 ± 1.74 vs. 3.28 ± 1.70). The differences between IRAT, GRAT, and retention test scores in the TBL group were significant. The mean student satisfaction score on a five-point scale was 3.01 ± 0.9 (median = 3) in the lecture group and 4.11 ± 1.1 (median = 4) in the TBL group. Our results seem encouraging for use of TBL performed with real patients in neurology education to achieve better long-term knowledge retention and higher in-class engagement and student satisfaction.

THE PROFILE OF MULTIPLE SCLEROSIS IN GENERAL PRACTICE

2015 ◽  
Vol 86 (11) ◽  
pp. e4.6-e4
Author(s):  
Sophie Binks ◽  
Liz Green
Keyword(s):  
Multiple Sclerosis ◽  
Primary Care ◽  
Team Approach ◽  
Improvement Project ◽  
Flu Vaccination ◽  
The Mean ◽  
One Year ◽  
Primary Care Professionals

IntroductionMultiple sclerosis (MS) is a long-term neurological condition requiring a multi-disciplinary team approach. Recently, NICE highlighted the role of primary care professionals in MS management through an updated clinical guideline. This quality improvement project investigated aspects of MS patient care in a large Brighton GP practice.MethodElectronic GP records were searched to identify all currently registered patients with a diagnosis of MS. Details of initial presentation, epidemiology and care received over a one-year period were examined.ResultsThere were 19 patients, representing a prevalence of 186 per 100,000. Most patients first presented in GP with sensory disturbance, optic neuritis or motor symptoms. The mean number of primary care contacts per patient per year was 4.3, compared to 0.4 contacts per person per year with a neurologist and 0.5 with the MS nurse. 46% of GP consultations were wholly or partially related to the patient's MS. Around half of patients took up proactive interventions such as flu vaccination (47%) and Vitamin D monitoring (50%).ConclusionsPrimary care professionals are significant contributors to the care of people with MS with frequent patient contact. During this project, patients were reminded of preventive care opportunities and this will be re-audited in 2015.

scholarly journals Sinus heart rate post pulmonary vein ablation and long-term risk of recurrences

2020 ◽  
Author(s):  
Gesa von Olshausen ◽  
Ott Saluveer ◽  
Jonas Schwieler ◽  
Nikola Drca ◽  
Hamid Bastani ◽  
...  
Keyword(s):  
Heart Rate ◽  
Pulmonary Vein ◽  
Heart Rate Change ◽  
Rate Change ◽  
Study Cohort ◽  
The Mean ◽  
One Year ◽  
The One ◽  
The Impact

Abstract Purpose Cather ablation is known to influence the autonomic nervous system. This study sought to investigate the association of sinus heart rate pre-/post-ablation and recurrences in patients with atrial fibrillation undergoing pulmonary vein isolation (PVI). Methods Between January 2012 and December 2017, data of 482 patients undergoing their first PVI were included. Sinus heart rate was recorded before (PRE), directly post-ablation (POST) and 3 months post-ablation (3 M). All patients were screened for atrial tachyarrhythmia recurrences during the one-year follow-up. Results In the total study cohort, the mean resting sinus heart rate at PRE [mean 57.9 bpm (95% CI 57.1–58.7 bpm)] increased by over 10 bpm to POST [mean 69.4 bpm (95% CI 68.5–70.3 bpm); p < 0.001] followed by a slight decrease at 3 M [mean 67.3 bpm (95% CI 66.4–68.2 bpm)] but still remaining higher compared to PRE (p < 0.001). This pattern was observed in patients with and without recurrences at POST and 3 M (both p < 0.001 compared to PRE). However, at 3 M the mean sinus heart rate was significantly lower in patients with compared to patients without recurrences (p = 0.031). In this regard, patients with a heart rate change < 11 bpm (PRE to 3 M) or, as an alternative parameter, patients with a heart rate < 60 bpm at 3 M had a significantly higher risk of recurrences compared to the remaining patients (Hazard ratio (HR) 1.82 (95% CI 1.32–2.49), p < 0.001 and HR 1.64 (95% CI 1.20–2.25), p = 0.002, respectively). Conclusion Our study confirms the impact of PVI on cardiac autonomic function with a significant sinus heart rate increase post-ablation. Patients with a sinus heart rate change < 11 bpm (PRE to 3 M) are at higher risk for recurrences during one-year post-PVI.

scholarly journals Long-Term Temporal Variability of the Freshwater Discharge and Water Levels at Patos Lagoon, Rio Grande do Sul, Brazil

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
G. P. Barros ◽  
W. C. Marques
Keyword(s):  
Ocean Circulation ◽  
Temporal Variability ◽  
Water Levels ◽  
Freshwater Discharge ◽  
Patos Lagoon ◽  
Mean Values ◽  
Physical Forcing ◽  
The Mean ◽  
One Year

The aim of this study is to investigate the importance of freshwater discharge as a physical forcing in Patos Lagoon at timescales longer than one year, as well as identify the temporal variability of the dominant processes in freshwater discharge and water levels along the Patos Lagoon. Due to its proximity to the mouth, the water level at the estuary is influenced by the remote effects associated with the adjacent ocean circulation and wave climatology, reducing the observed correlation. At the lagoonar region a high correlation is expected because interannual data is being used, reducing the influence of the wind. Cross wavelet technique is applied to examine the coherence and phase between interannual time-series (South Oscillation Index, freshwater discharge and water levels). The freshwater discharge of the main tributaries and water levels in Patos Lagoon are influenced by ENSO on interannual scales (cycles between 3.8 and 6 years). Therefore, El Niño events are associated with high mean values of freshwater discharge and water levels above the mean. On the other hand, La Niña events are associated with low mean values of freshwater discharge and water levels below the mean.

Consistency of Towing Speed and Sampling Depth for the Continuous Plankton Recorder

1993 ◽  
Vol 73 (4) ◽  
pp. 967-970 ◽  
Author(s):  
G. C. Hays ◽  
A. J. Warner
Keyword(s):  
Time Series ◽  
North Atlantic ◽  
Data Sets ◽  
Sampling Depth ◽  
The North ◽  
The North Sea ◽  
The Mean ◽  
Towing Speed ◽  
Term Data

The mean annual towing speed of the Continuous Plankton Recorder (CPR) varied systematically between 1946 and 1991. By mounting a pressure transducer on the CPR to record towing depth, it was shown, however, that changes in towing speed did not cause a significant change in towing depth, although the mean towing depth (6–7 m, SD=l-7 m, N=77) was shallower than the previously assumed towing depth of 10 m. Thus the observed changes in towing speed are unlikely to have caused discontinuities in the CPR time-series by affecting sampling depth.Long-term data sets play an important role in attempts to understand the causes of fluctua- tions in plankton abundance. The Continuous Plankton Recorder (CPR) survey provides multi- decadal information on plankton abundance in the North Sea and North Atlantic (McGowan, 1990), and is one of the longest standing marine plankton abundance time-series. However, while the CPR time-series has great potential, as with all other data sets spanning many years, questions may be asked regarding the consistency with which the data have been collected and hence the true continuity of the time-series.

Sign in / Sign up

Export Citation Format

Share Document