25 research outputs found
Circulation characteristics in three eddy-permitting models of the North Atlantic
A systematic intercomparison of three realistic eddy-permitting models of the North Atlantic circulation has been performed. The models use different concepts for the discretization of the vertical coordinate, namely geopotential levels, isopycnal layers, terrain-following (sigma) coordinates, respectively. Although these models were integrated under nearly identical conditions, the resulting large-scale model circulations show substantial differences. The results demonstrate that the large-scale thermohaline circulation is very sensitive to the model representation of certain localised processes, in particular to the amount and water
mass properties of the overflow across the Greenland-Scotland region, to the amount of mixing within a few hundred kilometers south of the sills, and to several other processes at small or sub-grid scales. The different behaviour of the three models can to a large extent be explained as a consequence of the different
model representation of these processes
Atlantic Equatorial Undercurrent and associated cold tongue variability
The Atlantic Equatorial Undercurrent (EUC) is studied using a simulation for the period 1990–2002 with a high-resolution ocean general circulation model. Simulated transports of the EUC that supplies the annual mean upwelling in the central and eastern equatorial Atlantic are in good agreement with new transport estimates derived from ship observations, i.e., 19.9 and 14.0 Sv at 35°W and 23°W, respectively. Although the observations are not conclusive concerning the seasonal cycle of EUC transports, the simulated seasonal cycles fit largely in the observed range. The analysis of the EUC variability associated with interannual boreal summer variability of the equatorial cold tongue showed that cold tongue indices, defined either by near-surface temperature or steric height anomalies, are anticorrelated with thermocline EUC transport anomalies: A strong EUC corresponds to low near-surface temperatures and steric heights. The importance of equatorial waves for the cold tongue region is shown: Surface layer transport anomalies at 23°W and 10°W are significantly correlated with both near-surface temperature and steric height anomalies in the equatorial and coastal upwelling regions, indicating an associated eastward phase propagation along the equator toward the African coast where the signal bifurcates into two poleward branches along the coast and is reflected into a westward propagating wave
Geographic Inequality in Income and Mortality in Germany
We use data from the German Federal Statistical Office on population counts, births, deaths and income to study the development of socio-economic inequality in mortality rates from 1990 to 2015 for different age groups and both genders. Ranking the 401 German districts by average disposable income per capita, we observe large inequalities in district-level mortality rates in 1990, which had almost disappeared, or at least been flattened considerably, by 2015 particularly for infants, children and the very old. The most important driver of this reduction in inequality is German reunification in 1990. As indicated by more detailed analyses comparing districts in the former East and the former West, even five years after reunification there was a large gap in disposable income, with all Eastern districts considerably poorer than the poorest district in the West. At the same time, mortality rates were higher for all age groups and both genders in the East. Income has caught up, to the extent that there are equally poor districts in the East and West in most recent years (although the West is still much richer on average). Mortality rates in the East have improved considerably and are even below mortality rates for similarly poor districts in the West in the most recent data
Fatigue increases ACL injury risk in youth athletes: Risk assessment study using drop-jump test
Objectives: The impact of fatigue on injury risk to the anterior cruciate ligament (ACL) in adolescent athletes is unknown. Identifying athletes who demonstrate increased risk for injury may help determine who would benefit from early neuromuscular control intervention for injury prevention. The goal of this study was to determine if fatigue increases ACL injury risk in adolescent athletes using the drop-jump test to assess dynamic valgus. Methods: Youth and adolescent competitive athletes were recruited for this video analysis study. Participants were recorded performing the standard drop-jump test assessing dynamic valgus on landing three times. They then completed a standardized fatigue protocol consisting of a timed period of high-intensity aerobic tasks. A set amount of fatigue was quantified and achieved using a maximum vertical jump, which was compared to pre-fatigue values. The drop-jump test was then repeated three additional times post-fatigue. All drop-jump recordings (six in total) were randomized by order and scored for dynamic knee valgus by three independent reviewers. A multivariable analysis was performed to assess the correlation between demographic variables and injury risk. Results: Forty-seven female patients and thirty-eight male athletes were included in the study. The average age was 15.4 years (age 14-18). Athletes were found to have significantly higher ACL injury risk post-fatigue when compared to pre-fatigue (p = .001). Thirty-five athletes were found to change from low/medium injury risk pre-fatigue to medium/high risk post fatigue. No demographic variables were found to contribute to ACL injury risk. Conclusion: In adolescent athletes, fatigue appears to increase risk of ACL injury through drop-jump testing. Age, BMI, and hip width were not found to contribute to ACL injury risk. Implementation of neuromuscular or conditioning programs for at-risk athletes may reduce injury risk
Fatigue Increases Dynamic Knee Valgus in Youth Athletes: Results From a Field-Based Drop-Jump Test.
PURPOSE: To determine whether fatigue increases dynamic knee valgus in adolescent athletes, as measured after a standardized exercise protocol and video-based drop-jump test. A secondary aim was to determine whether individual risk factors place certain athletes at increased risk for dynamic knee valgus.
METHODS: Athletes aged 14 to 18 years were recruited for this video analysis study. Athletes were recorded performing a standard drop-jump to assess dynamic valgus. Participants then completed a standardized exercise protocol. Fatigue was quantified using a maximum vertical jump, which was compared with pre-exercise values. The drop-jump was repeated postexercise. All drop-jump recordings were randomized and scored for dynamic valgus by 11 blinded reviewers. Univariate analysis was performed to identify characteristics that predisposed athletes to increased dynamic valgus.
RESULTS: Eighty-five (47 female, 38 male) athletes with an average age of 15.4 years were included in this study. Forty-nine percent of athletes demonstrated an increase in dynamic valgus determined by drop-jump assessment after exercise. A significantly greater percentage of athletes were graded medium or high risk in jumps recorded after the exercise protocol (68%) as compared with before the exercise protocol (44%; P \u3c .01). Female athletes (P \u3c .01) and those older than 15 years of age (P \u3c .01) were the most affected by fatigue.
CONCLUSIONS: In conclusion, our study found that exercise increases dynamic knee valgus in youth athletes. Female athletes and those older than 15 years of age were most significantly affected by exercise. Greater fatigue levels were found to correlate with an increase in dynamic knee valgus, which may place athletes at greater anterior cruciate ligament injury risk. The field-based exercise drop-jump test is a low-cost and reproducible screening tool to identify at-risk athletes who could possibly benefit from anterior cruciate ligament injury-prevention strategies.
LEVEL OF EVIDENCE: III, Comparative trial
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A novel MRI-based tumor-targeting theragnostic agent: Magnetoelectric nanoparticles in an in vivo murine KRAS / P53 pancreatic flank tumor model
3075 Background: Magnetoelectric nanoparticles (MENPs) are a novel material with a magnetoelectric (ME) property that allows for conversion of an external magnetic field to a local electric field (EF) that can be exploited to generate a Coulomb force to target and electroporate the relatively non-polarized tumor cell walls. We hypothesized that their local EF and superparamagnetic cores can be exploited as an MRI-based anti-cancer theragnostic agent for solid tumors. Methods: 35 immunocompetent C57BL/6 mice were inoculated with KPC961 pancreatic adenocarcinoma cells in their flank. The 27 mice with the largest tumors at 4 weeks were randomized into 5 cohorts based on treatment: 300 µg of MENP (300; n=6), 600 µg of MENP (600; n=6), 300 µg of low-ME coefficient MENP (LM; n=5), 300 µg of MENP without M1 MRI (NM; MRI field control, n=5), and normal saline (NS; MENP causal effect control; n=5). The 300, 600, LM, and NS cohorts had T 2 MRI maps (M0) on a 7T MRI. NM had T 2 weighted MRIs at M0. All mice had a neodymium magnet placed over their tumors for 12 hours after tail vein injections (300 µl for all mice) for targeting. The 300, 600, LM, and NS cohorts then underwent MRI mapping (M1) after magnet removal (No M1 MRI for NM). MRI mapping was repeated 5 days after (M2). NM had a T 2 weighted MRIs at M2. M1 and M2 data were used to assess relaxation time (contrast effect) and tumor volume from M0, respectively. Student t and ANOVA tests were used to compare differences for tumor volume and relaxation time data and one-sided Fisher’s exact test was used for complete response (CR) data. Results: The median M0 tumor volume was 109.6 mm 3 for all mice, and there were no differences between any cohort ( p = 0.978; Table). The 300 and 600 MENP cohorts demonstrated a 102.7% reduction in volume (M2/M0; 56.7% vs. 159.4% for NS and NM controls, p = <0.001) and a 7.2% T 2 negative contrast effect (M1/M0; 94.2% vs. 101.3% for NS, p = 0.046) compared to controls. Six mice in 300, 600, and LM (2 each) achieved a clinical CR (between 1 to 2 weeks after M1) vs. none in the NS and NM control cohorts ( p = 0.0418), without any recurrences until end of study (6 weeks after M2). Conclusions: This is the first report demonstrating the theragnostic effects of MENPs having both T 2 contrast and locally ablative therapy properties as an in vivo tumor targeting agent. These results confirm prior pilot study and point towards irreversible electroporation as the likely mechanism of action (MOA) since the antitumor effect is not seen within the NM cohort. Additional studies characterizing the MOA, dose-response relationships, and immunomodulatory effects are needed to better understand their full clinical potential.[Table: see text
Curating New Media
The proceedings of a conference at BALTIC, “Curating New Media” contains transcripts of the presentations of nine curators, artists, and artist-curators and the discussions between them about the production, distribution and exhibition of new media art. The speakers detail their experiences installing works on the Web and in galleries. Lists of participants, related URLs, and a corresponding programme of short films and videos are included. Biographical notes. 32 bibl. ref