30,749 research outputs found

    Fetal heterotaxy with tricuspid atresia, pulmonary atresia, and isomerism of the right atrial appendages at 22 weeks.

    Get PDF
    We report the accurate prenatal diagnosis at 22 weeks gestation of right atrial isomerism in association with tricuspid atresia. Several distinctive sonographic features of isomerism of the right atrial appendages were present in this fetus: complex cardiac abnormality, ventriculoarterial discordance, juxtaposition of the aorta and the inferior vena cava to the right side, pulmonary atresia, and anomalous pulmonary venous return to the morphological right atrium. Tricuspid atresia, which is an extremely rare lesion within heterotaxy spectrum disorders, was present. Postnatal investigations confirmed all prenatally diagnosed abnormalities, with additional findings of pulmonary atresia with discontinuous pulmonary arteries and bilateral arterial ducts, asplenia, and bilateral eparterial bronchi. To our knowledge, tricuspid atresia in the setting of isomerism of the right atrial appendages has not previously been diagnosed or reported prenatally. Because of the complexity of cardiac lesions that may be present in cases of atrial isomerism, these disorders should be considered even if sonographic findings are uncommon or atypical

    Development and flight test of an avionics LIDAR for helicopter and UAV low-level flight

    Get PDF
    In recent years, laser radar (LIDAR) has become a promising technology for navigation and obstacle avoidance in helicopters and UAV, mainly because of its good wire detection performance on a wide range of incidence angles, and also due to its outstanding range and accuracy. In this paper we describe the activities carried out for the design, integration and test of the Laser Obstacle Avoidance System 'Marconi' (LOAM) on helicopter and UAV platforms. After a brief description of the system architecture and sensor characteristics, emphasis is given to the performance models and processing algorithms required for obstacle detection/classification and calculation of alternative flight paths, as well as to the ground and flight test activities performed on various platforms

    On the direct indecomposability of infinite irreducible Coxeter groups and the Isomorphism Problem of Coxeter groups

    Full text link
    In this paper we prove, without the finite rank assumption, that any irreducible Coxeter group of infinite order is directly indecomposable as an abstract group. The key ingredient of the proof is that we can determine, for an irreducible Coxeter group, the centralizers of the normal subgroups that are generated by involutions. As a consequence, we show that the problem of deciding whether two general Coxeter groups are isomorphic, as abstract groups, is reduced to the case of irreducible Coxeter groups, without assuming the finiteness of the number of the irreducible components or their ranks. We also give a description of the automorphism group of a general Coxeter group in terms of those of its irreducible components.Comment: 30 page

    Resilience of the Internet of Things (IoT) from an Information Assurance (IA) Perspective

    Get PDF
    Internet infrastructure developments and the rise of the IoT Socio-Technical Systems (STS) have frequently generated more unsecure protocols to facilitate the rapid intercommunication between the plethoras of IoT devices. Whereas, current development of the IoT has been mainly focused on enabling and effectively meeting the functionality requirement of digital-enabled enterprises we have seen scant regard to their IA architecture, marginalizing system resilience with blatant afterthoughts to cyber defence. Whilst interconnected IoT devices do facilitate and expand information sharing; they further increase of risk exposure and potential loss of trust to their Socio-Technical Systems. A change in the IoT paradigm is needed to enable a security-first mind-set; if the trusted sharing of information built upon dependable resilient growth of IoT is to be established and maintained. We argue that Information Assurance is paramount to the success of IoT, specifically its resilience and dependability to continue its safe support for our digital economy

    Malaria, Intestinal Parasitic Infection, Anemia, and Malnourishment in Rural Cameroonian Villages with an Assessment of Early Interventions

    Get PDF
    Malaria, water-borne diarrheal diseases, and geohelminth infections, combined with severe malnutrition ravage entire villages throughout subSaharan Africa. The Bawa Health Initiative (BHI) is a 501c(3) non-profit organization with the goal of implementing a comprehensive public health program in an attempt to address these problems in a series of rural villages located in the West Province of Cameroon, Africa. Interventions include the provision of permethrin-treated bed nets to reduce the transmission of malaria, the installation of biosand water filters to reduce the prevalence of water-borne diseases, and a geohelminth control program utilizing mass treatment with albendazole. This study details the results of surveys conducted to monitor the success of the interventions. Since implementation of interventions, the number of clinical cases of malaria, diarrheal disease and typhoid has decreased, the prevalence of water-borne protozoan parasites has decreased, the prevalence and intensities of geohelminth infections has significantly decreased, and the prevalence of anemia has significantly decreased. When viewed in its entirety, these data show that the comprehensive approach to public health challenges in these villages initiated by BHI has been extremely successful. However, much work remains to be done. The primary purpose of this paper is to further inform academicians, students, and the general public about the continuing problems associated with these diseases and to describe and assess the effectiveness of some current interventions being used to combat them

    The biologically active iron chelators 2-pyridylcarboxaldehyde isonicotinoylhydrazone, 2-pyridylcarboxaldehyde benzoylhydrazone monohydrate and 2-furaldehyde isonicotinoylhydrazone

    Get PDF
    In the crystal structures of the respective title compounds, C12H10N4O, C13H11N3O . H2O and C11K9N3O2, variations in the torsion angles of the aromatic pyridyl and benzoyl groups are observed, and the disposition of the heterocyclic aldehyde is shown to be influenced by the ring size of this group

    Exploring the psychological rewards of a familiar semirural landscape: connecting to local nature through a mindful approach

    Get PDF
    This study analyses a 53,000 word diary of a year engaging with nature through over 200 trips to a semi-rural landscape. Thematic analysis revealed two themes; the transition from observer to nature connectedness and the ways in which the natural environment was experienced once a connection was made. These themes are discussed in relation to theories that seek to explain the positive effect of nature and nature connectedness. The findings are important as they suggest that repeated engagement with local semi-rural countryside can lead to a mindful approach and psychological rewards that do not require travel into the wilderness. The work informs further research into outcomes and processes of nature based interventions such as: trip frequency, duration and diary keeping

    Evidence for Proportionate Partition Between the Magnetic Field and Hot Gas in Turbulent Cassiopeia A

    Get PDF
    We present a deep X-ray observation of the young Galactic supernova remnant Cas A, acquired with the ROSAT High Resolution Imager. This high dynamic range (232 ks) image reveals low-surface-brightness X-ray structure, which appears qualitatively similar to corresponding radio features. We consider the correlation between the X-ray and radio morphologies and its physical implications. After correcting for the inhomogeneous absorption across the remnant, we performed a point by point (4" resolution) surface brightness comparison between the X-ray and radio images. We find a strong (r = 0.75) log-log correlation, implying an overall relationship of log⁥(ÎŁX−ray)∝(2.21±0.05)×log⁥(ÎŁradio)\log(\Sigma_{_{\rm X-ray}}) \propto (2.21\pm0.05) \times \log(\Sigma_{_{\rm radio}}). This is consistent with proportionate partition (and possibly equipartition) between the local magnetic field and the hot gas --- implying that Cas A's plasma is fully turbulent and continuously amplifying the magnetic field.Comment: 8 pages with embedded bitmapped figures, Accepted by ApJ Letters 5/1/9
    • 

    corecore