Analysing eye-tracking data: From scanpaths and heatmaps to the dynamic visualisation of areas of interest

International audienceTo understand the visual behaviors of people searching for information on Web pages, heatmaps and Areas Of Interest (AOI) are generally used. These two techniques bring interesting information on how Web pages are scanned by several users. However, two remarks can be expressed: the first one relates to the fact that heatmaps are usually used to represent fixation areas for a given task after it is completed. Thus, it does not represent fixation areas over time. The second remark relates to the use of AOI, which must be defined by the analyst. We present a method, which address these two points. This bottom-up approach is based on a mean-shift clustering procedure for the identification of areas of interest, which takes into account the temporal aspect. The identification of AOI is thus data driven. This approach allows us to show the evolution of a posteriori AOI both in space and time. The limitations and implications of this new approach are discusse

Isokinetic Fatigue Characteristics for the Leg Extensors versus Flexors

Maximal isokinetic muscle actions are often used in research studies to examine fatigability and even estimate muscle fiber-type. However, the majority of previous investigations have examined these topics for the leg extensors (i.e., quadriceps), and we are unaware of investigations that have specifically assessed the fatigue characteristics for the flexors (i.e., hamstrings). The purpose of this study was to compare the percent decline values for the leg extensors versus flexors for 50 and 100 repeated, maximal concentric isokinetic muscle actions. Fifteen healthy men (mean ± SD age = 23 ± 3 years; body mass = 94.1 ± 11.9 kg) with previous lower-body strength training experience volunteered to participate in this study. All of the subjects were familiarized with the testing procedures prior to data collection. For data collection, each subject performed 100 repeated, maximal concentric isokinetic muscle actions of the left leg extensors and flexors in a reciprocal manner. Each muscle action was performed at 180 degrees/second through a full 90 degree range of motion. Strong verbal encouragement was provided throughout testing. Percent decline was determined using the mean peak torque values of the initial and final three muscle actions for each muscle group (i.e., extensors versus flexors) and condition (i.e., 50 versus 100 repetitions). A two-way repeated measure analysis of variance was used to examine the data. The mean ± SD percent decline for the leg extensors was 61.8 ± 7.8 and 71.2 ± 6.5% for the 50 and 100 conditions, respectively (Cohen’s d = 1.31). For the leg flexors, these corresponding values were 48.0 ± 12.2 and 54.3 ± 11.7 % (Cohen’s d = 0.53). There was no significant muscle group × condition interaction (p= .114; partial eta squared = .169) There were, however, main effects for both factors. The bonferroni marginal mean pairwise comparisons indicated that when collapsed across condition, the leg extensors fatigued more so than the flexors (66.5 vs. 51.2%). Similarly, when collapsed across muscle group, the percent decline values were greater following 100 (62.8%) versus 50 (54.9%) repetitions. These finding demonstrated greater isokinetic fatigue characteristics for the leg extensors versus flexors. Furthermore, the additional decline in peak torque from repetitions 50-100 was more pronounced for the extensors. We speculate that these findings could be related to differences in muscle fiber-type, lower absolute strength and mass for the posterior aspect of the thigh, and/or unfamiliarity with single-joint testing of the leg flexors

Relationships Between Anthropometric and Performance Variables in Youth: Predictors of Lower-Body Vertical Jump Peak Power

ABSTRACT Anthropometric and physical performance measurements are commonly used for identifying specific physical traits in youth. Laboratory-based tests (e.g., linear velocity transducers), while accurate, provide practical limitations due to high costs and technical necessities. Thus, commonly used field tests may be useful alternatives for assessing fitness/performance characteristics of youth. The purpose of this study was to examine the relationships between anthropometric measures and lower-and upper-body power and strength measures; and to assess the predictive ability of these measures for lower-body vertical jump peak power (PP) output in youth. Thirty-nine pre-adolescent (mean±SD, range: age=7.8±1.7, 5-12 years) children volunteered to participate in this investigation. Subjects were measured for body mass and stature on a calibrated physicians scale. Lower-body PP was assessed using a linear velocity transducer, which was attached to the posterior side of a belt that was securely fastened to the subjects’ waistline. Subjects performed countermovement jumps, starting in a standing position, with hands placed on hips and feet firmly on the ground. Following the descent to the midpoint position and without pause, the subjects exploded upward as hard and fast as possible. Broad jump testing involved subjects performing a countermovement jump in the horizontal direction, on a scaled mat. Maximum isometric hand grip strength of the dominant hand was assessed using a dynamometer. For all testing, 1-2 practice trials were performed, followed by testing consisting of 2-3 trials. The highest trial was used for analyses. Peak power values were normalized to body mass using allometric scaling procedures (PP· body mass-0.67). Pearson correlation (r) and stepwise linear regression analyses were performed to examine the relationships. Results indicated all variables (age, stature, body mass, broad jump and grip strength) were significantly correlated (r=0.38-0.64) to PP. Age was correlated to all variables (r=0.39-0.82) and stature and body mass were correlated to all variables (r=0.37-0.77) except broad jump. Broad jump was correlated only to age (r=0.39) and PP (r=0.38). Linear regression for all variables revealed that stature was the only variable entered into the model (R=0.64; R2=0.41). With the anthropometric variables removed, grip strength was the only variable entered into the model (R=0.57; R2=0.32). These findings suggest that while all the anthropometric and performance variables may be correlated to PP, only stature and grip strength were effective, and thus, necessary to predict PP abilities. Interestingly, broad jump performance was not a good predictor of lower body vertical PP

ESA’s Soil Moisture and Ocean Salinity Mission - An overview on the mission’s performance and scientific results

European Geosciences Union General Assembly 2014 (EGU2014), 27 april - 2 may 2014, Vienna, Austria.-- 1 pageThe Soil Moisture and Ocean Salinity (SMOS) mission, launched on 2 November 2009, is the European Space Agency’s (ESA) second Earth Explorer Opportunity mission. The scientific objectives of the SMOS mission directly respond to the need for global observations of soil moisture and ocean salinity, two key variables used in predictive hydrological, oceanographic and atmospheric models. SMOS observations also provide information on the characterisation of ice and snow covered surfaces and the sea ice effect on ocean-atmosphere heat fluxes and dynamics, which affects large-scale processes of the Earth’s climate system. This paper will provide an overview on the various aspects of the SMOS mission, such as 1. The performance of the mission after more than 5 years in orbit: The SMOS mission has been in routine operations since May 2010, following the successful completion of the 6-months commissioning phase. The paper will summarise the technical and scientific status of the mission, including the status of the RFI detection and mitigation and its effect on the data products. SMOS has so far provided very reliable instrument operations, data processing and dissemination to users. The paper will also provide an overview on the MIRAS instrument performance, including the instrument calibration and level 1 brightness temperature data processing. 2. An overview on the SMOS data products: SMOS provides continuously level 1 (brightness temperature) and level 2 (soil moisture and ocean salinity) to its scientific user community since summer 2010. SMOS also provides brightness temperature data (level 1 data) to ECMWF in near-real time (NRT), who assimilates the data into their forecasting system. New services have been established to deliver a tailored NRT data product via the WMO’s GTS and EUMETSAT’s EUMETCast data dissemination systems to other operational agencies. This will open up new operational applications for SMOS data. Other data products are under development, responding to the requirements of the science community in particular in the area of hydrology, climate, land use and ship routing, namely a frozen soil indicator, data products for freeze/thaw periods, sea ice thickness and vegetation water content. 3. Provide an update on the overall validation approach and recent activities: SMOS data products are continuously improved and approach the scientific mission objectives. Validation activities are essential to ensure high data quality. ESA in collaboration with national agencies and institutions maintains a frame for validation activities such as reference sites, ground based observations as well as campaigns. The paper will provide an update on recent activities, such as the activities at DOME-C. 4. Summarise the collaboration with other space-borne L-band sensors, such as NASA’s Aquarius and SMAP missionsPeer Reviewe

p53 status correlates with histopathological response in patients with soft tissue sarcomas treated using isolated limb perfusion with TNF-α and melphalan

Background: Recombinant tumor necrosis factor-α (TNF-α) combined to melphalan is clinically administered through isolated limb perfusion (ILP) for regionally advanced soft tissue sarcomas of the limbs. In preclinical studies, wild-type p53 gene is involved in the regulation of cytotoxic action of TNF-α and loss of p53 function contributes to the resistance of tumour cells to TNF-α. The relationship between p53 status and response to TNF-α and melphalan in patients undergoing ILP is unknown. Patients and methods: We studied 110 cases of unresectable limbs sarcomas treated by ILP. Immunohistochemistry was carried out using DO7mAb, which reacts with an antigenic determinant from the N-terminal region of both the wild-type and mutant forms of the p53 protein, and PAb1620mAb, which reacts with the 1620 epitope characteristic of the wild-type native conformation of the p53 protein. The immunohistochemistry data were then correlated with various clinical parameters. Results: P53DO7 was found expressed at high levels in 28 patients, whereas PAb1620 was negative in 20. The tumours with poor histological response to ILP with TNF-α and melphalan showed significantly higher levels of p53-mutated protein. Conclusions: Our results might be a clue to a role of p53 protein status in TNF-α and melphalan response in clinical us

Structure, controlled release mechanisms and health benefits of pectins as an encapsulation material for bioactive food components

Encapsulation of food and feed ingredients is commonly applied to avoid the loss of functionality of bioactive food ingredients. Components that are encapsulated are usually sensitive to light, pH, oxygen or highly volatile. Also, encapsulation is also applied for ingredients that might influence taste. Many polymers from natural sources have been tested for encapsulation of foods. In the past few years, pectins have been proposed as emerging broadly applicable encapsulation materials. The reasons are that pectins are versatile and inexpensive, can be tailored to meet specific demands and provide health benefits. Emerging new insight into the chemical structure and related health benefits of pectins opens new avenues to use pectins in food and feed. To provide insight into their application potential, we review the current knowledge on the structural features of different pectins, their production and tailoring process for use in microencapsulation and gelation, and the impact of the pectin structure on health benefits and release properties in the gut, as well as processing technologies for pectin-based encapsulation systems with tailor-made functionalities. This is reviewed in view of application of pectins for microencapsulation of different sensitive food components. Although some critical factors such as tuning of controlled release of cargo in the intestine and the impact of the pectin production process on the molecular structure of pectin still need more study, current insight is that pectins provide many advantages for encapsulation of bioactive food and feed ingredients and are cost-effective

Hydrology and Earth System Sciences The International Soil Moisture Network: a data hosting facility for global in situ soil moisture measurements

Abstract. In situ measurements of soil moisture are invaluable for calibrating and validating land surface models and satellite-based soil moisture retrievals. In addition, longterm time series of in situ soil moisture measurements themselves can reveal trends in the water cycle related to climate or land cover change. Nevertheless, on a worldwide basis the number of meteorological networks and stations measuring soil moisture, in particular on a continuous basis, is still limited and the data they provide lack standardization of technique and protocol

Global snow mass measurements and the effect of stratigraphic detail on inversion of microwave brightness temperatures

Snow provides large seasonal storage of freshwater, and information about the distribution of snow mass as Snow Water Equivalent (SWE) is important for hydrological planning and detecting climate change impacts. Large regional disagreements remain between estimates from reanalyses, remote sensing and modelling. Assimilating passive microwave information improves SWE estimates in many regions but the assimilation must account for how microwave scattering depends on snow stratigraphy. Physical snow models can estimate snow stratigraphy, but users must consider the computational expense of model complexity versus acceptable errors. Using data from the National Aeronautics and Space Administration Cold Land Processes Experiment (NASA CLPX) and the Helsinki University of Technology (HUT) microwave emission model of layered snowpacks, it is shown that simulations of the brightness temperature difference between 19 GHz and 37 GHz vertically polarised microwaves are consistent with Advanced Microwave Scanning Radiometer-Earth Observing System (AMSR-E) and Special Sensor Microwave Imager (SSM/I) retrievals once known stratigraphic information is used. Simulated brightness temperature differences for an individual snow profile depend on the provided stratigraphic detail. Relative to a profile defined at the 10 cm resolution of density and temperature measurements, the error introduced by simplification to a single layer of average properties increases approximately linearly with snow mass. If this brightness temperature error is converted into SWE using a traditional retrieval method then it is equivalent to ±13 mm SWE (7% of total) at a depth of 100 cm. This error is reduced to ±5.6 mm SWE (3 % of total) for a two-layer model

Characterisation and use of β-lactoglobulin fibrils for microencapsulation of lipophilic ingredients and oxidative stability thereof

There is a growing interest in using fibrils from food grade protein, e.g. β-lactoglobulin, as functional ingredients. In the present study, the functionality of fibrillar β-lactoglobulin from whey protein isolate (WPI) was compared to native WPI in terms of interfacial dilatational rheology and emulsifying activity at acidic conditions (pH 2.0 and 3.0). We report here for the first time data on microencapsulation of fish oil by spray-drying as well as oxidative stability of the oil in emulsions and microcapsules in dependence of WPI conformation. WPI fibrils exerted a significantly higher elasticity at the oil–water (o/w) interface and a better emulsifying activity at a fixed oil content compared to native WPI. Microencapsulation efficiency was also higher with fibrillar WPI (>95%) compared to native WPI (∼90%) at pH 2.0 and a total oil and protein content of 40% and 2.2%, respectively, in the final powder. The oxidative deterioration was lower in emulsions and microcapsules prepared with fibrillar than with native WPI. This was attributed to improved interfacial barrier properties provided by fibrils and antioxidative effects of coexisting unconverted monomers, particularly hydrophilic peptides