241 research outputs found
Temporal dynamics of Chaoborus larvae (Diptera : Chaoboridae) in the tropical ecosystem (lake Ayamé I ; Côte d’Ivoire).
Chaoborus larvae are voracious predators of zooplankton able to change their specific composition and size structure. Thus they appear as competitors of fish. They also represent food for planktophage fish. The temporal dynamics of Chaoborus larvae was studied (from january to october 1997) in the fishery of Bakro (5°33’N and 3°15’W) situated in lake Ayamé I (Côte d’Ivoire). Two peaks of density were observed : the most pronouced in March (end of the major dry season) with 747 ind./m2, and another, less pronouced in June (end of the major rainy season), with 280 ind./m2. Differences between densities may well be explained by the advent of the rainy season which leads to a decline in trophic resources (zooplankton) and exposes Chaoborus larvae to predation by fish.Key-words : Chaoborus larvae, Dynamics, lake Ayamé I, Côte d’Ivoire,West Africa
Chronic necrotizing pulmonary aspergillosis presenting as bilateral pleural effusion: a case report
<p>Abstract</p> <p>Introduction</p> <p>Chronic necrotizing pulmonary aspergillosis is an uncommon subacute form of <it>Aspergillus </it>infection. It typically occurs in immunocompromised individuals and in those with underlying lung disease. This interesting case highlights the occurrence of this entity of aspergillosis in an immunocompetent middle-aged woman with atypical radiological findings. To the best of our knowledge this is the first case report of chronic necrotizing pulmonary aspergillosis presenting with pleural effusion.</p> <p>Case presentation</p> <p>Our patient was a 64-year-old Malay woman with a background history of epilepsy but no other comorbidities. She was a lifelong non-smoker. She presented to our facility with a six-month history of productive cough and three episodes of hemoptysis. An initial chest radiograph showed bilateral pleural effusion with bibasal consolidation. Bronchoscopy revealed a white-coated endobronchial tree and bronchoalveolar lavage culture grew <it>Aspergillus niger</it>. A diagnosis of chronic necrotizing pulmonary aspergillosis was made based on the clinical presentation and microbiological results. She responded well to treatment with oral itraconazole.</p> <p>Conclusions</p> <p>The radiological findings in chronic necrotizing pulmonary aspergillosis can be very diverse. This case illustrates that this condition can be a rare cause of bilateral pleural effusion.</p
Non-filamentary (VMCO) memory : a two- and three-dimensional study on switching and failure modes
In this work, for the first time, a set of two-and three-dimensional (3D) analysis techniques are combined to clarify the nature of resistive switching (RS) in state-of-the-art TiO2-based vacancy modulated conductive oxide (VMCO) memory. (1) A non-filamentary switching mechanism is observed. (2) The role of oxygen incorporation and motion in the TiO2 is demonstrated. (3) The oxygen profile inside scaled cells is measured and a RS-model based on the modulation of oxygen inside the stack is proposed. In addition, we perform the tomographic analysis of fully-fabricated devices with Scalpel SPM, thus probing in 3D the entire stack and the contribution of TiO2 grain boundaries (GBs) to the switching operations. Finally, devices failed by breakdown (BD) during cycling are characterized, identifying the formation of parasitic filaments as root-cause of the failure
Hydrocarbon pneumonitis following liquid paraffin aspiration during a fire-eating performance: a case report
<p>Abstract</p> <p>Introduction</p> <p>Hydrocarbon pneumonitis is an acute, intense pneumonitis resulting from aspiration of volatile hydrocarbon compounds with low viscosity and surface tension, most of which are members of the paraffin, naphthene and aromatic classes.</p> <p>Case presentation</p> <p>Six hours after participating in a party for teenagers, a 16-year-old boy developed dyspnea, cough, a fever (39°C) and chest pain. A chest radiograph showed infiltration in the right middle lobe. The patient reported alcohol abuse during the party and an episode of vomiting a few hours thereafter. He also reported practicing a fire-eating performance at the party using liquid paraffin, but was unaware of inhaling any of it. The radiographic infiltration was diagnosed as an aspiration pneumonia and he was treated at the local health center with antibiotics. Five days later, because of clinical deterioration, he was referred to a pulmonary clinic. A chest computed tomography scan was performed which showed consolidation with an air bronchogram in the right middle lobe and areas of atelectasis and ground glass opacities in the middle and lower right lobes. Spirometry revealed severe restriction of lung function. A bronchoscopy revealed inflamed, hyperemic mucosa. Bronchoalveolar lavage fluid revealed lipid-laden alveolar macrophages, which were detected by lipid staining, and neutrophilia. The patient was finally diagnosed with hydrocarbon pneumonitis and he was treated with systemic steroids and antibiotics. After 6 days of treatment there was complete clinical and significant radiologic regression.</p> <p>Conclusion</p> <p>Hydrocarbon pneumonitis should be included in the differential diagnosis of pneumonias. Recent exposure to volatile hydrocarbons provides a basis for clinical diagnosis, as symptoms and radiologic findings are not specific.</p
Atomic layer deposition of high-k dielectric layers on Ge and III-V MOS channels
Ge and III-V semiconductors are potential high performance channel materials for future CMOS devices. In this work, we have studied At. Layer Deposition (ALD) of high-k dielec. layers on Ge and GaAs substrates. We focus at the effect of the oxidant (H2O, O3, O2, O2 plasma) during gate stack formation. GeO2, obtained by Ge oxidn. in O2 or O3, is a promising passivation layer. The germanium oxide thickness can be scaled down below 1 nm, but such thin layers contain Ge in oxidn. states lower than 4+. Still, elec. results indicate that small amts. of Ge in oxidn. states lower than 4+ are not detrimental for device performance. Partial intermixing was obsd. for high-k dielec. and GeO2 or GaAsOx, suggesting possible correlations in the ALD growth mechanisms on Ge and GaAs substrates. [on SciFinder (R)
Discontinuous Galerkin method for multifluid Euler equations
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/106454/1/AIAA2013-2595.pd
Vibration Response Imaging: evaluation of rater agreement in healthy subjects and subjects with pneumonia
<p>Abstract</p> <p>Background</p> <p>We evaluated pulmonologists variability in the interpretation of Vibration response imaging (VRI) obtained from healthy subjects and patients hospitalized for community acquired pneumonia.</p> <p>Methods</p> <p>The present is a prospective study conducted in a tertiary university hospital. Twenty healthy subjects and twenty three pneumonia cases were included in this study. Six pulmonologists blindly analyzed images of normal subjects and pneumonia cases and evaluated different aspects of VRI images related to the quality of data aquisition, synchronization of the progression of breath sound distribution and agreement between the maximal energy frame (MEF) of VRI (which is the maximal geographical area of lung vibrations produced at maximal inspiration) and chest radiography. For qualitative assessment of VRI images, the raters' evaluations were analyzed by degree of consistency and agreement.</p> <p>Results</p> <p>The average value for overall identical evaluations of twelve features of the VRI image evaluation, ranged from 87% to 95% per rater (94% to 97% in control cases and from 79% to 93% per rater in pneumonia cases). Inter-rater median (IQR) agreement was 91% (82-96). The level of agreement according to VRI feature evaluated was in most cases over 80%; intra-class correlation (ICC) obtained by using a model of subject/rater for the averaged features was overall 0.86 (0.92 in normal and 0.73 in pneumonia cases).</p> <p>Conclusions</p> <p>Our findings suggest good agreement in the interpretation of VRI data between different raters. In this respect, VRI might be helpful as a radiation free diagnostic tool for the management of pneumonia.</p
Thoracic CT findings of novel influenza A (H1N1) infection in immunocompromised patients
The goal of this study is to describe the spectrum of initial and follow-up CT findings of novel influenza A (H1N1) infection in a series of immunocompromised patients. Eight immunocompromised patients with documented novel influenza A (H1N1) had CT imaging at our institution between May 2009 and August 2009. A total of 20 CTs (initial and follow-up) were reviewed for the presence, severity, and distribution of the following: ground glass opacity, consolidation, interlobular septal thickening, mosaic perfusion, airway wall thickening, airway dilatation, nodules, cysts, pleural effusion, pericardial effusion, lymphadenopathy, and air trapping. The most common findings were airway thickening/dilatation, peribronchial ground glass opacity, centrilobular nodules, and tree-in-bud opacities. Peripheral consolidation involving the lower lobes was also a common pattern. Findings frequently involved all lobes and were closely associated with either large or small airways. Two patients presented with atypical CT findings including focal lobar consolidation and patchy lower lobe consolidation with soft tissue centrilobular nodules. Most survivors showed near complete resolution of findings within 35 days. CT scans in immunocompromised patients with novel influenza H1N1 commonly show a strong airway predominance of findings or peripheral areas of consolidation involving the lower lobes. A subset of patients with novel influenza A (H1N1) will show findings not typical of viral infection
Outcomes and prognostic factors of non-HIV patients with pneumocystis jirovecii pneumonia and pulmonary CMV co-infection: A Retrospective Cohort Study
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