Introducing passive matched field acoustic tomography

In acoustic tomography sea-basin environmental parameters such as temperature profiles and current-velocities are derived, when ray propagation models are adopted, by the travel time estimates relative to the identifiable ray paths. The transmitted signals are either single frequency, or impulsive, or intermittent and deterministic. When the wavelength is comparable with the scale lengths present in the propagation scenario, Matched Field Tomography (MFT) is used, entailing the consideration of waveguide modes instead of rays. A new concept in tomography is introduced in the paper, that employs passively the noise emitted by ships of opportunity (cargoes, ferries) as source signals. The passive technique is acoustic-pollution-free, and if a basin is selected in which a regular ship traffic occurs data can be received on a regular schedule, with no transmission cost. A novel array pre-processor for passive tomography is introduced, such that the signal structure at the pre-processor output is nearly the same as that obtainable in the case of single-frequency source signals. Hence, at the pre-processor output all the tomographic inversion methods valid for active tomography employing single-frequency sources can be applied. The differences between active and passive tomography are pointed out and the potential of passive techniques is illustrated by simple propagation scenarios adopting either rays or waveguide modes

EMG Analysis and Motor Unit Recruitment in the Rectus Femoris of College Students

The rectus femoris works as part of the quadriceps muscle group to provide the force needed to generate very explosive movements during knee extension. Because many sports require explosive movements from the lower body, many strength coaches implement exercise routines that strengthen the muscles and prevent injuries. In the general population, activities using knee extension are essential in getting the full benefit of a designed exercise program. Muscle fibers provide the contractile force needed to accomplish a movement. Commonly, a deficiency is present in people who tend to favor one leg more than the other during activity. This is due to factors such as improper training, improper biomechanics, and joint injury. Having a strength imbalance from one leg to the other can strongly influence the amount of force generated, and therefore the amount of weight lifted. The purpose of this study was to determine whether these subjects had an imbalance in the contractile force of the rectus femoris. The participants were all kinesiology students in a Master’s degree program. Their age ranges from 22 years of age to 25 years of age. The instruments being used for this procedure are a leg extension machine and Biopac EMG. Each participant was required to perform five reps of a single leg extension for each leg, after determining maximum voluntary contraction. To analyze data that is collected. Data was analyzed using SPSS and Microsoft Excel. Muscle contractions were compared between and within subjects and compared from the participant’s dominant to non-dominant leg. For this particular study, the purpose was calculating whether the contractions are different from dominant leg to non-dominant leg. The results indicate that participants have a significant decrease in the contractile force from their dominant to non-dominant leg; significance was set at p\u3c.05. This study shows where coaches, trainers, and athletes need to focus on strength training to correct muscle imbalances. Imbalances could indicate that subjects are not trained properly, or they are favoring one leg while performing explosive maneuvers, or have an injury that prevents proper firing motor unit recruitment (1, 4)

Energy Expenditure and Economy During a Cycle Ergometer Test

Research has shown that submaximal cycle ergometer testing presents a reduced V02 max score when compared to that of the treadmill test. In this study, we compared a submaximal economy test on the Monark Cycle Ergometer. The purpose of this study was for each participant to perform the same test and compare economy, V02 ml/kg/min for a given workload, as well as calories burned between males and females during the nine minute test. By testing economy for each participant, we aim to determine whether males or females use oxygen more efficiently during testing. Before beginning the test, the Cosmed metabolic equipment was calibrated. The test was standardized to last for nine minutes at 70 rotations per minute and 1 kilopond of resistance. Based off of the comparison in V02 mL/kg/min and kCal mL/kg/min, the women had the highest V02 per given workload and also had the lowest calories burned. The women were the least efficient by having a higher V02 while working at the same intensity as the male participants. The research used to support this study indicates that there are two components for overall metabolic power during a dynamic leg exercise on the cycle ergometer; the power used to overcome the resistance applied to the ergometer and the rate of energy expenditure required to move the lower limbs without opposition against the opposition load (Girardis, Linnarsson, Moia, Pendergast, & Ferretti, 1999). It is also stated that during exercise at submaximal levels below lactate threshold the net V02 of the whole body is equivalent of the net rate of energy expenditure (Storer, Davis, & Caiozzo, 1990). The cycle ergometer is a good use to determine V02 by collecting expired air and the volume measured in the spirometer (Saltin & Astrand, 1967). For the results of this lab to be more accurate the resistance and intensity could have been changed at different stages of the test. This would have given and more accurate measure of the ability of each participant to reach the next stage of testing

Passive ocean acoustic tomography: theory and experiment

In this paper the Passive Ocean Acoustic Tomography (P-OAT) methodology is presented. This technique, avoiding the use of a dedicated active sound source, estimates the sea water temperature spatial distribution from the received noise emitted from ships of opportunity. The feasibility of the proposed methodology has been confirmed both by test-runs on semi-synthetic data and by the use of real acoustic and environmental data collected during INTIMATE00 experiment performed on October 2000 in the Atlantic Ocean off the Portuguese coasts

Pre-operational short-term forecasts for Mediterranean Sea biogeochemistry

Operational prediction of the marine environment is recognised as a fundamental research issue in Europe. We present a pre-operational implementation of a biogeochem- ical model for the pelagic waters of the Mediterranean Sea, developed within the framework of the MERSEA-IP Euro- pean project. The OPATM-BFM coupled model is the core of a fully automatic system that delivers weekly analyses and forecast maps for the Mediterranean Sea biogeochem- istry. The system has been working in its current configura- tion since April 2007 with successful execution of the fully automatic operational chain in 87% of the cases while in the remaining cases the runs were successfully accomplished af- ter operator intervention. A description of the system devel- oped and also a comparison of the model results with satel- lite data are presented, together with a measure of the model skill evaluated by means of seasonal target diagrams. Future studies will address the implementation of a data assimila- tion scheme for the biogeochemical compartment in order to increase the skill of the model’s performance

Advancing Marine Biogeochemical and Ecosystem Reanalyses and Forecasts as Tools for Monitoring and Managing Ecosystem Health

Ocean ecosystems are subject to a multitude of stressors, including changes in ocean physics and biogeochemistry, and direct anthropogenic influences. Implementation of protective and adaptive measures for ocean ecosystems requires a combination of ocean observations with analysis and prediction tools. These can guide assessments of the current state of ocean ecosystems, elucidate ongoing trends and shifts, and anticipate impacts of climate change and management policies. Analysis and prediction tools are defined here as ocean circulation models that are coupled to biogeochemical or ecological models. The range of potential applications for these systems is broad, ranging from reanalyses for the assessment of past and current states, and short-term and seasonal forecasts, to scenario simulations including climate change projections. The objectives of this article are to illustrate current capabilities with regard to the three types of applications, and to discuss the challenges and opportunities. Representative examples of global and regional systems are described with particular emphasis on those in operational or pre-operational use. With regard to the benefits and challenges, similar considerations apply to biogeochemical and ecological prediction systems as do to physical systems. However, at present there are at least two major differences: (1) biogeochemical observation streams are much sparser than physical streams presenting a significant hinderance, and (2) biogeochemical and ecological models are largely unconstrained because of insufficient observations. Expansion of biogeochemical and ecological observation systems will allow for significant advances in the development and application of analysis and prediction tools for ocean biogeochemistry and ecosystems, with multiple societal benefits

OPENMODS 2.0 “Instrument Jamming Meeting” report

Major achievements The feedback provided by potential users on their needs was very much appreciated. They underlined the importance of having: ● an easy to deploy instrument (i.e.: from small fishing boats); ● multi-parameter sensors in ONE device; ● less maintenance effort and prioritized the variables to measure. Although, there are technical limitations and different solutions and there is no one tool that can do everything, which is low cost, has high resolution and low maintenance, the outcomes of the platforms/sensors/communications working group meet the main requirements that emerged. Priority was given to: ● a platform that will operate in drifter mode which is extremely easy to deploy and perfect for studies associated with search and rescue operations (another need that has emerged). It also constantly guarantees the knowledge of the instrument position. The platform can be easily converted into the moored mode. ● temperature and pressure sensors. The sensors will be low -cost with the idea to replace them rather than calibrate them; ● LoRaWAN communications preferably with Bluetooth integration for the in-situ download of the data

HIV-1 Pre-Integration Complexes Selectively Target Decondensed Chromatin in the Nuclear Periphery

Integration of the double-stranded DNA copy of the HIV-1 genome into host chromosomal DNA is a requirement for efficient viral replication. Integration preferentially occurs within active transcription units, however chromosomal site specificity does not correlate with any strong primary sequence. To investigate whether the nuclear architecture may affect viral integration we have developed an experimental system where HIV-1 viral particles can be visualized within the nuclear compartment. Fluorescently labeled HIV-1 virions were engineered by fusing integrase, the viral protein that catalyzes the integration reaction, to fluorescent proteins. Viral tests demonstrate that the infectivity of fluorescent virions, including the integration step, is not altered as compared to wild-type virus. 3-D confocal microscopy allowed a detailed analysis of the spatial and temporal distribution of the pre-integration complexes (PICs) within the nucleus at different moments following infection; the fluorescently labeled PICs preferentially distribute in decondensed areas of the chromatin with a striking positioning in the nuclear periphery, while heterochromatin regions are largely disfavored. These observations provide a first indication of how the nuclear architecture may initially orient the selection of retroviral integration sites