42 research outputs found
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Vitamin B6 status over time and its relation to symptoms of carpal tunnel syndrome
Research suggests that, in individuals with carpal tunnel syndrome (CTS), low
plasma pyridoxal 5'-phosphate (PLP) concentrations are related to an increased incidence
and severity of symptoms associated with CTS. This study was designed to determine
the relationship between plasma and red blood cell PLP concentrations and the severity
and incidence of CTS symptoms. Thirty people with CTS were selected for a 9 month
exercise study. Subjects were divided into either vitamin users or non-vitamin users
based on supplement use data gathered at the beginning of the study. Blood was drawn at
1, 6 and 9 months. CTS symptoms questionnaires and health questionnaires were also
administered at these intervals. The symptoms questionnaires were used to gather data on
the frequency and nature of hand and wrist symptoms. Health questionnaires focused on
vitamin supplement usage including frequency, amount and length of use. Mean plasma
PLP, total plasma vitamin B6 and erythrocyte PLP concentrations were significantly
higher in the sixteen vitamin users when compared to the fourteen non-vitamin users
(p<0.001). While there was variation in plasma PLP and total plasma vitamin B6 over
time, within each group, there were no significant changes in any of the status measures
over the nine month period. Mean erythrocyte PLP concentration, in particular, was
stable over time. In vitamin users, the intensity of pain, numbness and tingling was
significantly higher when compared to non-vitamin users. In both groups, plasma PLP
was negatively correlated with pain. This correlation reached statistical significance in
vitamin users at month one and nine (p<0.01), but not at month six; a statistically
significant correlation between these two variables was not found in non-vitamin users at
any time point. Pain was also negatively and significantly correlated with plasma total
vitamin B6 and erythrocyte PLP in vitamin users. No other symptoms were significantly
correlated with the status measures. These results indicate that a higher vitamin B6 status
may be related to a decrease in the severity of pain experienced by some individuals with
CTS
Effect of the UAV orientation in antenna pattern measurements
A novel radiation pattern measurement system for VHF and UHF antennas has been recently developed using the Unmanned Aerial Vehicle (UAV) technology. This paper discusses the effect of the UAV orientation and the applicable corrections on the pattern extraction procedure, in order to increase the accuracy and repeatability of the measurements
The UAV-based test source as an end-to-end verification tool for aperture arrays
A UAV-mounted radio-frequency transmitter is proposed as a known reference field source to perform a set of functional tests on aperture arrays. The experimental results obtained on complete prototypes (end-to-end) and sub-assemblies provide good confidence on both amplitude and timing verification
Sardinia Array Demonstrator: Instrument Overview and Status
In the framework of the Square Kilometer Array (SKA) project, the Italian Institute for Astrophysics (INAF) has addressed several efforts in the design and prototyping of aperture arrays for low-frequency radio astronomical research. The Sardinia Array Demonstrator (SAD) is a national project aimed to develop know-how in this area and to test different architectural technologies and calibration algorithms. SAD consists of 128 prototypical dual-polarized Vivaldi antennas designed to operate at radio frequencies below 650 MHz. The antennas will be deployed at the Sardinia Radio Telescope’s site with a versatile approach able to provide two different array configurations: (i) all antennas grouped in one large station or (ii) spread among a core plus few satellite stations. This paper provides an overview of the SAD project from an instrumental point of view, and illustrates its status after 2 years from its start
Subclonal diversification of primary breast cancer revealed by multiregion sequencing.
The sequencing of cancer genomes may enable tailoring of therapeutics to the underlying biological abnormalities driving a particular patient's tumor. However, sequencing-based strategies rely heavily on representative sampling of tumors. To understand the subclonal structure of primary breast cancer, we applied whole-genome and targeted sequencing to multiple samples from each of 50 patients' tumors (303 samples in total). The extent of subclonal diversification varied among cases and followed spatial patterns. No strict temporal order was evident, with point mutations and rearrangements affecting the most common breast cancer genes, including PIK3CA, TP53, PTEN, BRCA2 and MYC, occurring early in some tumors and late in others. In 13 out of 50 cancers, potentially targetable mutations were subclonal. Landmarks of disease progression, such as resistance to chemotherapy and the acquisition of invasive or metastatic potential, arose within detectable subclones of antecedent lesions. These findings highlight the importance of including analyses of subclonal structure and tumor evolution in clinical trials of primary breast cancer
The Sardinia Radio Telescope . From a technological project to a radio observatory
Context. The Sardinia Radio Telescope (SRT) is the new 64 m dish operated by the Italian National Institute for Astrophysics (INAF). Its active surface, comprised of 1008 separate aluminium panels supported by electromechanical actuators, will allow us to observe at frequencies of up to 116 GHz. At the moment, three receivers, one per focal position, have been installed and tested: a 7-beam K-band receiver, a mono-feed C-band receiver, and a coaxial dual-feed L/P band receiver. The SRT was officially opened in September 2013, upon completion of its technical commissioning phase. In this paper, we provide an overview of the main science drivers for the SRT, describe the main outcomes from the scientific commissioning of the telescope, and discuss a set of observations demonstrating the scientific capabilities of the SRT. Aims: The scientific commissioning phase, carried out in the 2012-2015 period, proceeded in stages following the implementation and/or fine-tuning of advanced subsystems such as the active surface, the derotator, new releases of the acquisition software, etc. One of the main objectives of scientific commissioning was the identification of deficiencies in the instrumentation and/or in the telescope subsystems for further optimization. As a result, the overall telescope performance has been significantly improved. Methods: As part of the scientific commissioning activities, different observing modes were tested and validated, and the first astronomical observations were carried out to demonstrate the science capabilities of the SRT. In addition, we developed astronomer-oriented software tools to support future observers on site. In the following, we refer to the overall scientific commissioning and software development activities as astronomical validation. Results: The astronomical validation activities were prioritized based on technical readiness and scientific impact. The highest priority was to make the SRT available for joint observations as part of European networks. As a result, the SRT started to participate (in shared-risk mode) in European VLBI Network (EVN) and Large European Array for Pulsars (LEAP) observing sessions in early 2014. The validation of single-dish operations for the suite of SRT first light receivers and backends continued in the following year, and was concluded with the first call for shared-risk early-science observations issued at the end of 2015. As discussed in the paper, the SRT capabilities were tested (and optimized when possible) for several different observing modes: imaging, spectroscopy, pulsar timing, and transients
Processed pseudogenes acquired somatically during cancer development
Cancer evolves by mutation, with somatic reactivation of retrotransposons being one such mutational process. Germline retrotransposition can cause processed pseudogenes, but whether this occurs somatically has not been evaluated. Here we screen sequencing data from 660 cancer samples for somatically acquired pseudogenes. We find 42 events in 17 samples, especially non-small cell lung cancer (5/27) and colorectal cancer (2/11). Genomic features mirror those of germline LINE element retrotranspositions, with frequent target-site duplications (67%), consensus TTTTAA sites at insertion points, inverted rearrangements (21%), 5′ truncation (74%) and polyA tails (88%). Transcriptional consequences include expression of pseudogenes from UTRs or introns of target genes. In addition, a somatic pseudogene that integrated into the promoter and first exon of the tumour suppressor gene, MGA, abrogated expression from that allele. Thus, formation of processed pseudogenes represents a new class of mutation occurring during cancer development, with potentially diverse functional consequences depending on genomic context
Signatures of mutational processes in human cancer.
All cancers are caused by somatic mutations; however, understanding of the biological processes generating these mutations is limited. The catalogue of somatic mutations from a cancer genome bears the signatures of the mutational processes that have been operative. Here we analysed 4,938,362 mutations from 7,042 cancers and extracted more than 20 distinct mutational signatures. Some are present in many cancer types, notably a signature attributed to the APOBEC family of cytidine deaminases, whereas others are confined to a single cancer class. Certain signatures are associated with age of the patient at cancer diagnosis, known mutagenic exposures or defects in DNA maintenance, but many are of cryptic origin. In addition to these genome-wide mutational signatures, hypermutation localized to small genomic regions, 'kataegis', is found in many cancer types. The results reveal the diversity of mutational processes underlying the development of cancer, with potential implications for understanding of cancer aetiology, prevention and therapy
Meeting in the middle: TVET programs’ education-employment linkage in developing contexts
Technical and vocational education and training (TVET) programs are most successful at supporting youth labor markets when they combine education and employment. Education-employment linkage theory describes this combination in terms of power-sharing between actors from the education system and their counterparts in the employment system over key processes in the curriculum value chain of curriculum design, curriculum application (program delivery), and curriculum updating. The KOF Education-Employment Linkage Index measures linkage at every function in a TVET program where actors from the two systems interact, aggregating those into processes and phases and eventually an index score. We apply that index to the largest upper-secondary TVET programs in Benin, Chile, Costa Rica, and Nepal. We find that Benin has relatively high education-employment linkage, while the other three countries score very low. Benin’s situation is unique because its TVET program is moving from employer-led to linked, rather than the typical employer integration into an education-based program. Other countries with large informal economies, low formal education and training rates, and existing non-formal employer-led training may be able to implement similar approaches using functionally equivalent institutions. Furthermore, we summarize the results of discussions with policy-maker focus groups in the four case study countries
Meeting in the Middle: TVET Programs’ Education–Employment Linkage at Different Stages of Development
Technical and vocational education and training (TVET) programs are most successful at supporting youth labor markets when they combine education and employment. Education–employment linkage theory describes this combination in terms of power-sharing between actors from the education system and their counterparts in the employment system over key processes in the curriculum value chain of curriculum design, curriculum application (program delivery), and curriculum updating. The Education–Employment Linkage Index measures linkage for every function in a TVET program where actors from the two systems interact, aggregating those into processes and phases and eventually an index score. We apply this index to the largest upper-secondary TVET programs in Benin, Chile, Costa Rica, and Nepal. We find that Benin has relatively high education–employment linkage, while the other three countries score very low. Benin’s situation is unique because its TVET program is moving from employer-led to linked, rather than the typical employer integration into an education-based program. Other countries with large informal economies, low formal education and training rates, and existing non-formal employer-led training may be able to implement similar approaches