Indoor air quality in schools of a highly polluted south Mediterranean area

This study aimed at surveying lower secondary schools in southern Italy, in a highly polluted area. A community close to an industrial area and three villages in rural areas was investigated. Indoor temperature, relative humidity (RH), gaseous pollutants (CO₂ and NO₂), selected biological pollutants in indoor dust, and the indoor/outdoor mass concentration and elemental composition of PM_2.5 were ascertained. Temperature and RH were within, or close to, the comfort range, while CO₂ frequently exceeded the threshold of 1000 ppm, indicating inadequate air exchange rate. In all the classrooms, median NO₂ levels were above the WHO threshold value. Dermatophagoides p. allergen concentration was below the sensitizing threshold, while high endotoxin levels were detected in the classrooms, suggesting schools may produce significant risks of endotoxin exposure. Concentration and solubility of PM_2.5 elements were used to identify the sources of indoor particles. Indoor concentration of most elements was higher than outdoors. Resuspension was responsible for the indoor increase in soil components. For elements from industrial emission (Cd, Co, Ni, Pb, Sb, Tl, V), the indoor concentration depended on penetration from the outside. For these elements, differences in rural vs industrial concentrations were found, suggesting industrial sources may influence indoor air quality nearby schools.     

Epstein-Barr virus-related primary cutaneous amyloidosis. Successful treatment with acyclovir and interferon-alpha

Cutaneous lesions related to chronic active Epstein-Barr virus (EBV) infection have been rarely documented in immunocompetent patients. A 30-year-old woman, fulfilling the diagnostic criteria for the chronic fatigue syndrome, had a 10-year history of pruritic brownish macules and papules on her chest and back. Her EBV serology was abnormal; the EBV genome was present in the epidermis of lesions, in oral secretions, and in peripheral mononuclear cells (PMC). Her blood lymphocytes spontaneously outgrew in culture. Histology revealed deposits of amyloid in the papillary dermis. Treatment with acyclovir and interferon-alpha rapidly improved her condition, stopped the lymphocyte outgrowth in culture, and reduced the EBV DNA content in oral secretions and in PMC. These data support an endogenous reactivation of EBV infection and suggest a causal relationship with primary amyloidosis.     

Chronic fatigue syndrome: a novel disorder with cutaneous manifestations

Effects of heating and 60cobalt (60Co) irradiation to hepatitis C virus (HCV) RNA in sera were studied. HCV-RNA can not be detected by PCR in 10 positive serum samples after being heated at 56 degrees C for 10 hours. Whereas, HCV-RNA can still be detected in positive sera after being lyophilized and then heated at 60 degrees C for 20 hours. It suggested heating at 56 degrees C for 10 hours can inactivate HCV in sera and the sera should be in liquid status when thermal inactivation is taken. Lyophilized sera with thermal inactivation for HCV should be inactivated first and then lyophilized. But the safety of sera with heat-treatment should be further investigated. Inactivation of HCV in sera with 60Co irradiation needed extra large dose of it, and protein components in sera would obviously be altered. Therefore, inactivation of HCV in sera with 60Co irradiation is impractical.     

Human herpesvirus 7 in patients with pityriasis rosea. Electron microscopy investigations and polymerase chain reaction in mononuclear cells, plasma and skin

BACKGROUND: Clinical evidence suggests a viral etiology for pityriasis rosea (PR). OBJECTIVE: To evaluate human herpesvirus (HHV)-6 and HHV-7 as candidates for the etiology of PR. METHODS: Blood and skin tissue from 12 patients with acute PR, and 12 patients with other dermatoses were studied, as well as blood samples from 25 healthy persons. Serum interferon (IFN)-alpha and IFN-gamma were analyzed by ELISA. Analysis of morphological changes in cocultured peripheral blood mononuclear cells (PBMC) and electron microscopy (EM) to identify viral particles were performed. Polymerase chain reaction (PCR) with specific primers for HHV-6 and HHV-7 DNA sequences was performed on the plasma and PBMC of patients and healthy controls and on the skin of patients with PR and other skin diseases. RESULTS: PR plasma contained detectable IFN-alpha and IFN-gamma, whereas plasma from controls did not. PBMC from PR patients showed ballooning cells and syncytia after 7 days in culture whereas PBMC from controls and recovered PR patients did not. This cytopathic effect was also documented in a PR patient who relapsed and in Sup-T1 cell cultures inoculated with the cell-free supernatant from centrifuged cultured PBMC; in this supernatant, herpesvirus, virions were detected by EM, PCR identified HHV-7 DNA in PBMC, plasma and skin from all patients with active PR and in the PBMC only of 5 patients tested 10-14 months later. Weaker signals of HHV-7 DNA were detected in PBMC of 11 controls, but not in their plasma. Skin was negative for HHV-7 in all control specimens. CONCLUSIONS: Although the detection of HHV-7 DNA in PBMC and tissues does not prove directly a causal role, HHV-7 DNA in cell-free plasma corresponds to active replication which supports a causal relationship. We propose that PR is a clinical presentation of HHV-7 reactivation.     

Two Degrees of Freedom in the Control of a DC-DC Boost Converter,Fuzzy Identified Explicit Model in Feed-forward Line

We present a novel approach to the fuzzy control of a DC-DC Boost Converter. Using heuristic partitioning of the main control parameters and focusing on global knowledge of the open-loop, stable system’s equilibriums, the new method is developed based on an offline fuzzy identification of the steadystate duty cycle. The explicit and the fuzzy identified global model of the duty cycle robustly contribute to the system’s stability, even in the presence of large changes to the process parameters. In comparison with the analytically derived duty cycle using two different methods, the identified model prediction of an infinity horizon duty cycle shows better precision. These results are achieved in an analysis of the converter’s hybrid-simulation model where the assumptions made in the mathematical modelling are minor in comparison with similar assumptions in physical examples. The steady-state error compensation relies on the optimized PI controller, which is independently constructed and involved in the final Two-Degreesof-Freedom (TDOF) controller. The successful simulation results agree with the robustness and present a DC-DC converter with stable operation, even in the dynamic exchange of the DCM (Discontinuous Conduction Mode) and CCM (Continuous Conduction Mode). The method is widely applicable as it minimizes the real time of processing and avoids over-determined solutions.     

A control strategy for platoons of differential drive wheeled mobile robot

The strategy for the control of vehicle platooning is proposed and tested on different mobile robot platforms. The decentralized platooning is considered, i.e. a virtual train of vehicles where each vehicle is autonomous and decides on its motion based on its own perceptions. The following vehicle only has information about its distance and azimuth to the leading vehicle. Its position is determined using odometry. The reference position and the orientation of the following vehicle are determined by the estimated path of the leading vehicle in a parametric polynomial form. The parameters of the polynomials are determined using the least-squares method. This parametric reference path is also used to determine the feed-forward part and to suppress tracking errors by a feed-back part of the applied globally stable nonlinear control law. The results of the experiment and simulations demonstrate the applicability of the proposed algorithm for vehicle platoons.     

Modeling and Control of MM-UAV: Mobile Manipulating Unmanned Aerial Vehicle

Compared to autonomous ground vehicles, UAVs (unmanned aerial vehicles) have significant mobility advantages and the potential to operate in otherwise unreachable locations. Micro UAVs still suffer from one major drawback: they do not have the necessary payload capabilities to support high performance arms. This paper, however, investigates the key challenges in controlling a mobile manipulating UAV using a commercially available aircraft and a light-weight prototype 3-arm manipulator. Because of the overall instability of rotorcraft, we use a motion capture system to build an efficient autopilot. Our results indicate that we can accurately model and control our prototype system given significant disturbances when both moving the manipulators and interacting with the ground.