178 research outputs found
From Connectivity to Advanced Internet Services: A Comprehensive Review of Small Satellites Communications and Networks
Recently the availability of innovative and affordable COTS (Commercial Off The Shelf) technological solutions
and the ever improving results of microelectronics and microsystems technologies have enabled the design of ever
smaller yet ever more powerful satellites. The emergence of very capable small satellites heralds an era of new
opportunities in the commercial space market. Initially applied only to scientific missions, earth observation and
remote sensing, small satellites are now being deployed to support telecommunications services. This review paper
examines the operational features of small satellites that contribute to their success. An overview of recent advances
and development trends in the field of small satellites is provided, with a special focus on telecommunication aspects
such as the use of higher frequency bands, optical communications, new protocols, and advanced architectures
Fast optical investigation of cardiac electrophysiology by parallel detection in multiwell plates
Current techniques for fast characterization of cardiac electrophysiology employ optical technologies to control and monitor action potential features of single cells or cellular monolayers placed in multiwell plates. High-speed investigation capacities are commonly achieved by serially analyzing well after well employing fully automated fluorescence microscopes. Here, we describe an alternative cost-effective optical approach (MULTIPLE) that exploits high-power LED arrays to globally illuminate a culture plate and an sCMOS sensor for parallel detection of the fluorescence coming from multiple wells. MULTIPLE combines optical detection of action potentials using a red-shifted voltage-sensitive fluorescent dye (di-4-ANBDQPQ) with optical stimulation, employing optogenetic actuators, to ensure excitation of cardiomyocytes at constant rates. MULTIPLE was first characterized in terms of interwell uniformity of the illumination intensity and optical detection performance. Then, it was applied for probing action potential features in HL-1 cells (i.e., mouse atrial myocyte-like cells) stably expressing the blue light-activatable cation channel CheRiff. Under proper stimulation conditions, we were able to accurately measure action potential dynamics across a 24-well plate with variability across the whole plate of the order of 10%. The capability of MULTIPLE to detect action potential changes across a 24-well plate was demonstrated employing the selective K(v)11.1 channel blocker (E-4031), in a dose titration experiment. Finally, action potential recordings were performed in spontaneous beating human induced pluripotent stem cell derived cardiomyocytes following pharmacological manipulation of their beating frequency. We believe that the simplicity of the presented optical scheme represents a valid complement to sophisticated and expensive state-of-the-art optical systems for high-throughput cardiac electrophysiological investigations.Cardiolog
Seasonal and inter-annual variability in nutrient supply in relation to mixing in the Bay of Biscay
Post-print
Evolving and sustaining ocean best practices and standards for the next decade
The oceans play a key role in global issues such as climate change, food security, and human health. Given their vast dimensions and internal complexity, efficient monitoring and predicting of the planet's ocean must be a collaborative effort of both regional and global scale. A first and foremost requirement for such collaborative ocean observing is the need to follow well-defined and reproducible methods across activities: from strategies for structuring observing systems, sensor deployment and usage, and the generation of data and information products, to ethical and governance aspects when executing ocean observing. To meet the urgent, planet-wide challenges we face, methods across all aspects of ocean observing should be broadly adopted by the ocean community and, where appropriate, should evolve into "Ocean Best Practices." While many groups have created best practices, they are scattered across the Web or buried in local repositories and many have yet to be digitized. To reduce this fragmentation, we introduce a new open access, permanent, digital repository of best practices documentation (oceanbestpractices.org) that is part of the Ocean Best Practices System (OBPS). The new OBPS provides an opportunity space for the centralized and coordinated improvement of ocean observing methods. The OBPS repository employs user-friendly software to significantly improve discovery and access to methods. The software includes advanced semantic technologies for search capabilities to enhance repository operations. In addition to the repository, the OBPS also includes a peer reviewed journal research topic, a forum for community discussion and a training activity for use of best practices. Together, these components serve to realize a core objective of the OBPS, which is to enable the ocean community to create superior methods for every activity in ocean observing from research to operations to applications that are agreed upon and broadly adopted across communities. Using selected ocean observing examples, we show how the OBPS supports this objective. This paper lays out a future vision of ocean best practices and how OBPS will contribute to improving ocean observing in the decade to come
A compilation of global bio-optical in situ data for ocean colour satellite applications â version three
A global in situ data set for validation of ocean colour products from the ESA Ocean Colour Climate
Change Initiative (OC-CCI) is presented. This version of the compilation, starting in 1997, now extends to
2021, which is important for the validation of the most recent satellite optical sensors such as Sentinel 3B
OLCI and NOAA-20 VIIRS. The data set comprises in situ observations of the following variables: spectral remote-sensing reflectance, concentration of chlorophyll-a, spectral inherent optical properties, spectral diffuse
attenuation coefficient, and total suspended matter. Data were obtained from multi-project archives acquired via
open internet services or from individual projects acquired directly from data providers. Methodologies were
implemented for homogenization, quality control, and merging of all data. Minimal changes were made on the
original data, other than conversion to a standard format, elimination of some points, after quality control and
averaging of observations that were close in time and space. The result is a merged table available in text format.
Overall, the size of the data set grew with 148 432 rows, with each row representing a unique station in space
and time (cf. 136 250 rows in previous version; Valente et al., 2019). Observations of remote-sensing reflectance
increased to 68 641 (cf. 59 781 in previous version; Valente et al., 2019). There was also a near tenfold increase
in chlorophyll data since 2016. Metadata of each in situ measurement (original source, cruise or experiment,
principal investigator) are included in the final table. By making the metadata available, provenance is better
documented and it is also possible to analyse each set of data separately. The compiled data are available at
https://doi.org/10.1594/PANGAEA.941318 (Valente et al., 2022)
Evolving and sustaining ocean best practices and standards for the next decade
The oceans play a key role in global issues such as climate change, food security, and human health. Given their vast dimensions and internal complexity, efficient monitoring and predicting of the planetâs ocean must be a collaborative effort of both regional and global scale. A first and foremost requirement for such collaborative ocean observing is the need to follow well-defined and reproducible methods across activities: from strategies for structuring observing systems, sensor deployment and usage, and the generation of data and information products, to ethical and governance aspects when executing ocean observing. To meet the urgent, planet-wide challenges we face, methods across all aspects of ocean observing should be broadly adopted by the ocean community and, where appropriate, should evolve into âOcean Best Practices.â While many groups have created best practices, they are scattered across the Web or buried in local repositories and many have yet to be digitized. To reduce this fragmentation, we introduce a new open access, permanent, digital repository of best practices documentation (oceanbestpractices.org) that is part of the Ocean Best Practices System (OBPS). The new OBPS provides an opportunity space for the centralized and coordinated improvement of ocean observing methods. The OBPS repository employs user-friendly software to significantly improve discovery and access to methods. The software includes advanced semantic technologies for search capabilities to enhance repository operations. In addition to the repository, the OBPS also includes a peer reviewed journal research topic, a forum for community discussion and a training activity for use of best practices. Together, these components serve to realize a core objective of the OBPS, which is to enable the ocean community to create superior methods for every activity in ocean observing from research to operations to applications that are agreed upon and broadly adopted across communities. Using selected ocean observing examples, we show how the OBPS supports this objective. This paper lays out a future vision of ocean best practices and how OBPS will contribute to improving ocean observing in the decade to come
Anterolateral Ligament Expert Group consensus paper on the management of internal rotation and instability of the anterior cruciate ligament - deficient knee
Purpose of this paper is to provide an overview of the latest research on the anterolateral ligament (ALL) and present the consensus of the ALL Expert Group on the anatomy, radiographic landmarks, biomechanics, clinical and radiographic diagnosis, lesion classification, surgical technique and clinical outcomes. A consensus on controversial subjects surrounding the ALL and anterolateral knee instability has been established based on the opinion of experts, the latest publications on the subject and an exchange of experiences during the ALL Experts Meeting (November 2015, Lyon, France). The ALL is found deep to the iliotibial band. The femoral origin is just posterior and proximal to the lateral epicondyle; the tibial attachment is 21.6 mm posterior to Gerdy's tubercle and 4-10 mm below the tibial joint line. On a lateral radiographic view the femoral origin is located in the postero-inferior quadrant and the tibial attachment is close to the centre of the proximal tibial plateau. Favourable isometry of an ALL reconstruction is seen when the femoral position is proximal and posterior to the lateral epicondyle, with the ALL being tight upon extension and lax upon flexion. The ALL can be visualised on ultrasound, or on T2-weighted coronal MRI scans with proton density fat-suppressed evaluation. The ALL injury is associated with a Segond fracture, and often occurs in conjunction with acute anterior cruciate ligament (ACL) injury. Recognition and repair of the ALL lesions should be considered to improve the control of rotational stability provided by ACL reconstruction. For high-risk patients, a combined ACL and ALL reconstruction improves rotational control and reduces the rate of re-rupture, without increased postoperative complication rates compared to ACL-only reconstruction. In conclusion this paper provides a contemporary consensus on all studied features of the ALL. The findings warrant future research in order to further test these early observations, with the ultimate goal of improving the long-term outcomes of ACL-injured patients. Level of evidence Level V-Expert opinion
FM-UWB for communications and radar in medical applications
UWB echnology is a useful and safe newtechnology in the area of wireless body
area network. There are many advantages of using UWB as a communication standard for
biomedical applications. Due to very low radiated power (â41.3 dBm/MHz), low power consumption,
good coexistence with the other existing instruments, Robustness to interference
andmultipath. Moreover, one specificUWBtechnology, namely FrequencyModulated (FM)-
UWB, has also an important advantage, which make it even more convenient for medical
applications, such as simple lowcost design (FM, no receive LO, no carrier synchronization as
in IR-UWB).UWBtechnology has been also proposed radar applications such as: Non-Invasive
Heart and Respiration Rate Monitoring; Detection of Cardiac Arrhythmias; Detection
of Pathological Respiratory Patterns, particularly in Sudden Infant Death Syndrome (SIDS)
and Sleep Apnea; Multi-Patient Monitoring; Detection and Non-Invasive Imaging of Breast
Tumors. However, pulsed radar are mainly used for these applications. The main issue that
is addressed in this paper is the integration of sensing and communication using FM-UWB
and radar technology so that a single device can be obtained for two different operational
mode.We have show that FM-UWB as radar can meet the requirements of typical biomedical
applications such as Non-Invasive Heart and Respiration Rate Monitoring. Advantages and
challenges of this integration are shown. Future perspectives of this novel activity will be
drawn
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