160 research outputs found

    Implementation of a suite of components for Software Defined Radio using an SCA-compliant framework

    Get PDF
    The aim of this work is to introduce Software Defined Radio (SDR) technology, present an open source SCA-compliant framework whose name is Redhawk, which derives from the OSSIE project and describes an implementation example of some processing instances. Since in SDR applications it is necessary to run the same software on different hardware, portability becomes the main important aspect in the development of software radio applica- tions. The use of a SCA-compliant framework solves this issue making hardware transparent to the programmer and reducing time and costs of code development. This aspect can be exploited for prototyping applications quickly without the need of a spe- cific hardware or testing new standards and protocols. We will introduce some basic concepts of SDR, of the SCA architecture, based on CORBA, and Redhawk. We will then talk about of the implementation of a suite of components, writ- ten by using Redhawk IDE and C++ programming language. These will be tied together to form an application called waveform. We will also present the results obtained by enforcing a certain level of parallelism in our algorithm to speed up computation in Redhawk components and boost performances against a more simpler non concurrent implementation of the same algorithms

    Stereotyping of medical disability claimants' communication behaviour by physicians: towards more focused education for social insurance physicians

    Get PDF
    Background: Physicians who hold medical disability assessment interviews (social insurance physicians) are probably influenced by stereotypes of claimants, especially because they have limited time available and they have to make complicated decisions. Because little is known about the influences of stereotyping on assessment interviews, the objectives of this paper were to qualitatively investigate: (1) the content of stereotypes used to classify claimants with regard to the way in which they communicate; (2) the origins of such stereotypes; (3) the advantages and disadvantages of stereotyping in assessment interviews; and (4) how social insurance physicians minimise the undesirable influences of negative stereotyping. Methods: Data were collected during three focus group meetings with social insurance physicians who hold medical disability assessment interviews with sick-listed employees (i.e. claimants). The participants also completed a questionnaire about demographic characteristics. The data were qualitatively analysed in Atlas.ti in four steps, according to the grounded theory and the principle of constant comparison. Results: A total of 22 social insurance physicians participated. Based on their responses, a claimant's communication was classified with regard to the degree of respect and acceptance in the physician-claimant relationship, and the degree of dominance. Most of the social insurance physicians reported that they classify claimants in general groups, and use these classifications to adapt their own communication behaviour. Moreover, the social insurance physicians revealed that their stereotypes originate from information in the claimants' files and first impressions. The main advantages of stereotyping were that this provides a framework for the assessment interview, it can save time, and it is interesting to check whether the stereotype is correct. Disadvantages of stereotyping were that the stereotypes often prove incorrect, they do not give the complete picture, and the claimant's behaviour changes constantly. Social insurance physicians try to minimise the undesirable influences of stereotypes by being aware of counter transference, making formal assessments, staying neutral to the best of their ability, and being compassionate. Conclusions: We concluded that social insurance physicians adapt their communication style to the degree of respect and dominance of claimants in the physician-claimant relationship, but they try to minimise the undesirable influences of stereotypes in assessment interviews. It is recommended that this issue should be addressed in communication skills trainin

    The quick motor function test: a new tool to rate clinical severity and motor function in Pompe patients

    Get PDF
    Pompe disease is a lysosomal storage disorder characterized by progressive muscle weakness. With the emergence of new treatment options, psychometrically robust outcome measures are needed to monitor patients’ clinical status. We constructed a motor function test that is easy and quick to use. The Quick Motor Function Test (QMFT) was constructed on the basis of the clinical expertise of several physicians involved in the care of Pompe patients; the Gross Motor Function Measure and the IPA/Erasmus MC Pompe survey. The test comprises 16 items. Validity and test reliability were determined in a cohort of 91 Pompe patients (5 to 76 years of age). In addition, responsiveness of the scale to changes in clinical condition over time was examined in a subgroup of 18 patients receiving treatment and 23 untreated patients. Interrater and intrarater reliabilities were good (intraclass correlation coefficients: 0.78 to 0.98 and 0.76 to 0.98). The test correlated strongly with proximal muscle strength assessed by hand held dynamometry and manual muscle testing (rs= 0.81, rs=0.89), and showed significant differences between patient groups with different disease severities. A clinical-empirical exploration to assess responsiveness showed promising results, albeit it should be repeated in a larger group of patients. In conclusion, the Quick Motor Function Test can reliably rate clinical severity and motor function in children and adults with Pompe disease

    Principal component approach in variance component estimation for international sire evaluation

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>The dairy cattle breeding industry is a highly globalized business, which needs internationally comparable and reliable breeding values of sires. The international Bull Evaluation Service, Interbull, was established in 1983 to respond to this need. Currently, Interbull performs multiple-trait across country evaluations (MACE) for several traits and breeds in dairy cattle and provides international breeding values to its member countries. Estimating parameters for MACE is challenging since the structure of datasets and conventional use of multiple-trait models easily result in over-parameterized genetic covariance matrices. The number of parameters to be estimated can be reduced by taking into account only the leading principal components of the traits considered. For MACE, this is readily implemented in a random regression model.</p> <p>Methods</p> <p>This article compares two principal component approaches to estimate variance components for MACE using real datasets. The methods tested were a REML approach that directly estimates the genetic principal components (direct PC) and the so-called bottom-up REML approach (bottom-up PC), in which traits are sequentially added to the analysis and the statistically significant genetic principal components are retained. Furthermore, this article evaluates the utility of the bottom-up PC approach to determine the appropriate rank of the (co)variance matrix.</p> <p>Results</p> <p>Our study demonstrates the usefulness of both approaches and shows that they can be applied to large multi-country models considering all concerned countries simultaneously. These strategies can thus replace the current practice of estimating the covariance components required through a series of analyses involving selected subsets of traits. Our results support the importance of using the appropriate rank in the genetic (co)variance matrix. Using too low a rank resulted in biased parameter estimates, whereas too high a rank did not result in bias, but increased standard errors of the estimates and notably the computing time.</p> <p>Conclusions</p> <p>In terms of estimation's accuracy, both principal component approaches performed equally well and permitted the use of more parsimonious models through random regression MACE. The advantage of the bottom-up PC approach is that it does not need any previous knowledge on the rank. However, with a predetermined rank, the direct PC approach needs less computing time than the bottom-up PC.</p

    Induction of labour versus expectant monitoring in women with pregnancy induced hypertension or mild preeclampsia at term: the HYPITAT trial

    Get PDF
    Contains fulltext : 53183.pdf ( ) (Open Access)BACKGROUND: Hypertensive disorders, i.e. pregnancy induced hypertension and preeclampsia, complicate 10 to 15% of all pregnancies at term and are a major cause of maternal and perinatal morbidity and mortality. The only causal treatment is delivery. In case of preterm pregnancies conservative management is advocated if the risks for mother and child remain acceptable. In contrast, there is no consensus on how to manage mild hypertensive disease in pregnancies at term. Induction of labour might prevent maternal and neonatal complications at the expense of increased instrumental vaginal delivery rates and caesarean section rates. METHODS/DESIGN: Women with a pregnancy complicated by pregnancy induced hypertension or mild preeclampsia at a gestational age between 36+0 and 41+0 weeks will be asked to participate in a multi-centre randomised controlled trial. Women will be randomised to either induction of labour or expectant management for spontaneous delivery. The primary outcome of this study is severe maternal morbidity, which can be complicated by maternal mortality in rare cases. Secondary outcome measures are neonatal mortality and morbidity, caesarean and vaginal instrumental delivery rates, maternal quality of life and costs. Analysis will be by intention to treat. In total, 720 pregnant women have to be randomised to show a reduction in severe maternal complications of hypertensive disease from 12 to 6%. DISCUSSION: This trial will provide evidence as to whether or not induction of labour in women with pregnancy induced hypertension or mild preeclampsia (nearly) at term is an effective treatment to prevent severe maternal complications. TRIAL REGISTRATION: The protocol is registered in the clinical trial register number ISRCTN08132825

    Hypertrophy of mature xenopus muscle fibres in culture induced by synergy of albumin and insulin

    Get PDF
    The aim of this study was to investigate effects of albumin and insulin separately as well as in combination on mature muscle fibres during long-term culture. Single muscle fibres were dissected from m. iliofibularis of Xenopus laevis and attached to a force transducer in a culture chamber. Fibres were cultured in a serum-free medium at slack length (mean sarcomere length 2.3 μm) for 8 to 22 days. The medium was supplemented with (final concentrations): (1) bovine insulin (6 nmol/L or 200-600 nmol/L), (2) 0.2% bovine albumin or (3) 0.2% bovine albumin in combination with insulin (120 nmol/L). In culture medium with insulin, 50% of the muscle fibres became in-excitable within 7-12 days, whereas the other 50% were stable. Caffeine contractures of in-excitable muscle fibres produced 80.4±2.4% of initial peak tetanic force, indicating impaired excitation-contraction (E-C) coupling in in-excitable fibres. In the presence of albumin, all cultured muscle fibres were stable for at least 10 days. Muscle fibres cultured in medium with insulin or albumin exclusively did not hypertrophy or change the number of sarcomeres in series. In contrast, muscle fibres cultured with both albumin and insulin showed an increase in tetanic force and fibre cross-sectional area of 19.6±2.8% and 32.5±4.9%, respectively, (means±SEM.; P=0.007) after 16.3±1.7 days, whereas the number of sarcomeres in series remained unchanged. We conclude that albumin prevents muscle fibre damage and preserves E-C coupling in culture. Furthermore, albumin is important in regulating muscle fibre adaptation by a synergistic action with growth factors like insulin. © 2008 The Author(s)

    Uncovering Suitable Reference Proteins for Expression Studies in Human Adipose Tissue with Relevance to Obesity

    Get PDF
    Protein expression studies based on the two major intra-abdominal human fat depots, the subcutaneous and the omental fat, can shed light into the mechanisms involved in obesity and its co-morbidities. Here we address, for the first time, the identification and validation of reference proteins for data standardization, which are essential for accurate comparison of protein levels in expression studies based on fat from obese and non-obese individuals.To uncover adipose tissue proteins equally expressed either in omental and subcutaneous fat depots (study 1) or in omental fat from non-obese and obese individuals (study 2), we have reanalyzed our previously published data based on two-dimensional fluorescence difference gel electrophoresis. Twenty-four proteins (12 in study 1 and 12 in study 2) with similar expression levels in all conditions tested were selected and identified by mass spectrometry. Immunoblotting analysis was used to confirm in adipose tissue the expression pattern of the potential reference proteins and three proteins were validated: PARK7, ENOA and FAA. Western Blot analysis was also used to test customary loading control proteins. ENOA, PARK7 and the customary loading control protein Beta-actin showed steady expression profiles in fat from non-obese and obese individuals, whilst FAA maintained steady expression levels across paired omental and subcutaneous fat samples.ENOA, PARK7 and Beta-actin are proper reference standards in obesity studies based on omental fat, whilst FAA is the best loading control for the comparative analysis of omental and subcutaneous adipose tissues either in obese and non-obese subjects. Neither customary loading control proteins GAPDH and TBB5 nor CALX are adequate standards in differential expression studies on adipose tissue. The use of the proposed reference proteins will facilitate the adequate analysis of proteins differentially expressed in the context of obesity, an aim difficult to achieve before this study

    The bisphosphonate pamidronate induces apoptosis in human melanoma cells in vitro

    Get PDF
    Pamidronate belongs to the class of nitrogen-containing bisphosphonates that are potent inhibitors of bone resorption frequently used for the treatment of osteoporosis and cancer-induced osteolysis. The inhibition of osteoclasts’ growth has been suggested as the main mechanism of the inhibitory effect of pamidronate on bone metastases. Recent findings indicated that bisphosphonates also have a direct apoptotic effect on other types of tumour cells. Nitrogen-containing bisphosphonates were shown to inhibit farnesyl diphosphate synthase, thus blocking the synthesis of higher isoprenoids. By this mechanism they inactivate monomeric G-proteins of the Ras and Rho families for which prenylation is a functional requirement. On the background of the known key role of G-proteins in tumorigenesis, we investigated a possible beneficial use of pamidronate in the treatment of malignant melanoma. Our results indicate that pamidronate inhibits the cell growth and induces apoptosis in human melanoma cells in vitro. Susceptibility to pamidronate did not correlate to CD95 ligand sensitivity or p53 mutational status. Furthermore it is interesting to note that overexpression of bcl-2 did not abolish pamidronate-induced apoptosis. These data suggests that pamidronate has a direct anti-tumour effect on malignant melanoma cells, independently of the Bax/Bcl-2 level

    A Validated Model of Serum Anti-Müllerian Hormone from Conception to Menopause

    Get PDF
    Background Anti-Müllerian hormone (AMH) is a product of growing ovarian follicles. The concentration of AMH in blood may also reflect the non-growing follicle (NGF) population, i.e. the ovarian reserve, and be of value in predicting reproductive lifespan. A full description of AMH production up to the menopause has not been previously reported. Methodology/Principal Findings By searching the published literature for AMH concentrations in healthy pre-menopausal females, and using our own data (combined ) we have generated and robustly validated the first model of AMH concentration from conception to menopause. This model shows that 34% of the variation in AMH is due to age alone. We have shown that AMH peaks at age 24.5 years, followed by a decline to the menopause. We have also shown that there is a neonatal peak and a potential pre-pubertal peak. Our model allows us to generate normative data at all ages. Conclusions/Significance These data highlight key inflection points in ovarian follicle dynamics. This first validated model of circulating AMH in healthy females describes a transition period in early adulthood, after which AMH reflects the progressive loss of the NGF pool. The existence of a neonatal increase in gonadal activity is confirmed for females. An improved understanding of the relationship between circulating AMH and age will lead to more accurate assessment of ovarian reserve for the individual woman.Publisher PDFPeer reviewe

    Comparing unilateral and bilateral upper limb training: The ULTRA-stroke program design

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>About 80% of all stroke survivors have an upper limb paresis immediately after stroke, only about a third of whom (30 to 40%) regain some dexterity within six months following conventional treatment programs. Of late, however, two recently developed interventions - constraint-induced movement therapy (CIMT) and bilateral arm training with rhythmic auditory cueing (BATRAC) - have shown promising results in the treatment of upper limb paresis in chronic stroke patients. The ULTRA-stroke (acronym for Upper Limb TRaining After stroke) program was conceived to assess the effectiveness of these interventions in subacute stroke patients and to examine how the observed changes in sensori-motor functioning relate to changes in stroke recovery mechanisms associated with peripheral stiffness, interlimb interactions, and cortical inter- and intrahemispheric networks. The present paper describes the design of this single-blinded randomized clinical trial (RCT), which has recently started and will take several years to complete.</p> <p>Methods/Design</p> <p>Sixty patients with a first ever stroke will be recruited. Patients will be stratified in terms of their remaining motor ability at the distal part of the arm (i.e., wrist and finger movements) and randomized over three intervention groups receiving modified CIMT, modified BATRAC, or an equally intensive (i.e., dose-matched) conventional treatment program for 6 weeks. Primary outcome variable is the score on the Action Research Arm test (ARAT), which will be assessed before, directly after, and 6 weeks after the intervention. During those test sessions all patients will also undergo measurements aimed at investigating the associated recovery mechanisms using haptic robots and magneto-encephalography (MEG).</p> <p>Discussion</p> <p>ULTRA-stroke is a 3-year translational research program which aims (1) to assess the relative effectiveness of the three interventions, on a group level but also as a function of patient characteristics, and (2) to delineate the functional and neurophysiological changes that are induced by those interventions.</p> <p>The outcome on the ARAT together with information about changes in the associated mechanisms will provide a better understanding of how specific therapies influence neurobiological changes, and which post-stroke conditions lend themselves to specific treatments.</p> <p>Trial Registration</p> <p>The ULTRA-stroke program is registered at the Netherlands Trial Register (NTR, <url>http://www.trialregister.nl</url>, number NTR1665).</p
    corecore