Tool support for the design and management of context models

A central task in the development of context-aware applications is the modeling and management of complex context information. In this paper, we present the NexusEditor, which can ease this task by providing a graphical user interface to design schemas for spatial and technical context models, interactively create queries, send them to a server and visualize the results. One main contribution is to show how schema awareness can improve such a tool: The NexusEditor dynamically parses the underlying data model and provides additional syntactic checks, semantic checks, and short-cuts based on the schema information. Furthermore, the tool helps to design new schema definitions based on the existing ones, which is crucial for an iterative and user-centric development of context-aware applications. Finally, it provides interfaces to existing information spaces and visualization tools for spatial data like GoogleEarth.     

On the Shared Control of an EMG-Controlled Prosthetic Hand: Analysis of User–Prosthesis Interaction

An anthropomorphic underactuated prosthetic hand, endowed with position and force sensors and controlled by means of myoelectric commands, is used to perform experiments of hierarchical shared control. Three different hierarchical control strategies combined with a vibrotactile feedback system have been developed and tested by able-bodied subjects through grasping tasks used in activities of daily living (ADLs). The first goal is to find a good tradeoff between good grasping capabilities and low attention required by the user to complete grasping tasks, without addressing advanced algorithm for electromyographic processing. The second goal is to understand whether a vibrotactile feedback system is subjectively or objectively useful and how it changes users' performance. Experiments showed that users were able to successfully operate the device in the three control strategies, and that the grasp success increased with more interactive control. Practice has proven that when too much effort is required, subjects do not do their best, preferring, instead, a less-interactive control strategy. Moreover, the experiments showed that when grasping tasks are performed under visual control, the enhanced proprioception offered by a vibrotactile system is practically not exploited. Nevertheless, in subjective opinion, feedback seems to be quite important.     

Role of bronchoalveolar lavage in predicting survival of patients with human immunodeficiency virus infection

In this multicenter study, we investigated the prognostic factors that influence the risk of death in patients with human immunodeficiency virus (HIV) infection. Clinical and laboratory indices obtained from 161 HIV-seropositive patients who underwent a detailed morphologic and immunophenotypic evaluation of bronchoalveolar lavage (BAL) and peripheral blood cell populations were retrospectively analyzed. In 155 patients, death occurred within the 48-mo follow-up (mean follow-up: 14.8 mo; range: 1 to 48 mo). In the univariate analysis, the patient's age (> 30 yr), HIV disease status, HIV transmission category, number of opportunistic pathogens isolated from the BAL, percentage of BAL neutrophils, and low number of BAL CD4 T cells were predictive of increased mortality. In contrast, the presence of an alveolitis or an increase in the numbers of alveolar macrophages and CD3 T cells was associated with a decreased mortality. In the multivariate analysis, significant independent predictors were age, risk factor for HIV, and presence of an alveolitis. Furthermore, patients with a low number of BAL CD4 T cells had a particularly poor prognosis while the CD4 T-cell count in the peripheral blood (< 50 cells/mm3 in the majority of our patients) had a negligible effect on predicting survival. Our findings suggest the clinical utility of BAL analysis in patients infected with HIV.     

The Role of Low-Energy Electron Interactions in cis-Pt(CO)2Br2 Fragmentation

Platinum coordination complexes have found wide applications as chemotherapeutic anticancer drugs in synchronous combination with radiation (chemoradiation) as well as precursors in focused electron beam induced deposition (FEBID) for nano-scale fabrication. In both applications, low-energy electrons (LEE) play an important role with regard to the fragmentation pathways. In the former case, the high-energy radiation applied creates an abundance of reactive photo- and secondary electrons that determine the reaction paths of the respective radiation sensitizers. In the latter case, low-energy secondary electrons determine the deposition chemistry. In this contribution, we present a combined experimental and theoretical study on the role of LEE interactions in the fragmentation of the Pt(II) coordination compound cis-PtBr₂(CO)₂. We discuss our results in conjunction with the widely used cancer therapeutic Pt(II) coordination compound cis-Pt(NH₃)₂Cl₂ (cisplatin) and the carbonyl analog Pt(CO)₂Cl₂, and we show that efficient CO loss through dissociative electron attachment dominates the reactivity of these carbonyl complexes with low-energy electrons, while halogen loss through DEA dominates the reactivity of cis-Pt(NH₃)₂Cl₂.     

Imipramine in alopecia areata. A double-blind, placebo-controlled study

Alopecia areata (AA) is a dermatologic disease whose onset is significantly associated to life events. Its course may often be characterized by high levels of anxiety and depression. These observations suggested a rationale for using an antidepressant in AA. Thirteen patients were enrolled in a double-blind, placebo-controlled study of efficacy of imipramine in alopecia. After six months clinically significant hair regrowth occurred in 5 of the 7 patients on imipramine, whereas no response was observed in the placebo group. An improvement in psychic symptomatology was present in both groups. Our preliminary results indicate the potential efficacy of imipramine in patients with AA, not acting directly through a reduction of anxiety or depression.     

The role of a bidirectional cavopulmonary anastomosis in the correction and palliation of complex congenital cardiopathies

Between May 1990 and January 1998, 68 patients underwent bidirectional cavo-pulmonary anastomosis. We evaluated all patients in whom the bidirectional cavo-pulmonary anastomosis was associated with additional pulmonary flow (group A) and those in whom it was associated with biventricular repair (group B). Group A included 23 patients (33.8%), 14 males and 9 females, mean age 25 years and 6 months (range 4 months-16 years). Diagnoses were double outlet right ventricle (6), univentricular heart (6), tricuspid atresia (5), congenitally-corrected transposition of the great arteries with ventricular septal defect and pulmonary stenosis (3), right isomerism (2) and pulmonary atresia with atrioventricular canal (1). Group B included 13 patients (19.1%), 6 males and 7 females, mean age 13 years and 7 months (range 1 year-37 years). Diagnoses were pulmonary atresia with intact ventricular septum (4), Ebstein's anomaly (3), tetralogy of Fallot (3), atrioventricular canal (1), hypoplastic right ventricle (1), and pulmonary and tricuspid insufficiency (1). Four patients (17.3%) in group A died in the postoperative period, whereas there was no postoperative mortality in group B. Follow-up data were available in 31 patients (19 from group A, 13 from group B). Mean follow-up was 1 year and 6 months (range 30 days to 6 years). Evaluation was done by NYHA class functional status. In group A, 14 patients are doing well (NYHA I or II), while five patients (26.3%) underwent Fontan operation with one death. All group B patients are currently doing well (NYHA class I or II). In group A, complications were pericardial effusion (7), transient superior vena cava syndrome (5), pleural effusion (4), chylothorax (1) and rhythm disturbance (1). Complications in group B involved neurological events (2), pleural effusion (1) and rhythm disturbance (1). Bidirectional cavo-pulmonary anastomosis can be associated with additional pulmonary flow with good short- and intermediate-term outcome. Concern remains for the ability to properly regulate the amount of effective pulmonary blood flow. Bidirectional cavo-pulmonary anastomosis can be associated with biventricular repair in patients with diminutive right ventricles, amenable to anatomic complete correction, with good clinical outcome.     

Cerebral autoregulation in patients with cirrhosis and ascites. A transcranial Doppler study

BACKGROUND/AIMS: Patients with cirrhosis and ascites usually show alterations of systemic hemodynamics and are thus prone to develop arterial hypotension, which might result in cerebral hypoperfusion if cerebral autoregulation is impaired. METHODS: We evaluated cerebral autoregulation in 15 patients with cirrhosis and ascites and 15 healthy subjects by monitoring mean blood flow velocity in the middle cerebral artery and arterial pressure during supine rest and passive tilting. RESULTS: Tilt provoked a drop of arterial pressure in both groups. Control subjects had a prompt recovery of mean flow velocity and a progressive recovery of arterial pressure, so that, after 120 s, both parameters had returned to baseline: at 20 s the recovery of flow velocity was faster (p<0.01) than that of blood pressure. By contrast, patients with cirrhosis had a delayed and incomplete recovery of both parameters (p<0.01 vs healthy subjects). In eight patients, the recovery of mean flow velocity paralleled that of arterial pressure, indicating an impaired cerebral autoregulation. These patients had a worse liver function, a higher cardiac index and lower peripheral resistance. CONCLUSIONS: Cerebral autoregulation is often impaired in patients with cirrhosis and ascites. These patients can develop cerebral hypoperfusion if arterial pressure falls abruptly.