Seroprevalence of Bordetella pertussis antibodies in adults in Hungary: results of an epidemiological cross-sectional study.

BACKGROUND: Pertussis (whooping cough) is well known to be underreported, particularly among adults, who can act as an infectious reservoir, potentially putting susceptible newborns at risk of serious illness. The purpose of this study was to estimate the seroprevalence of pertussis in adults in Hungary. METHODS: This epidemiological, cross-sectional study was conducted in adults in five general practitioners' practices in Hungary. Serum anti-pertussis toxin immunoglobulin G (anti-PT IgG) antibody levels were analyzed using enzyme-linked immunosorbent assay. Sera were classified following manufacturer's instructions as: strongly indicative of current/recent infection (>/=1.5 optical density [OD] units); indicative of current/recent infection (>/=1.0 OD units); seropositive (>0.3 OD units); or seronegative (/=60 years (odds ratio [OR], 1.97; 95% confidence interval [CI], 1.39-2.80; p = .0002) or 18-29 years (OR, 1.67; 95% CI, 1.13-2.46; p = .0094) vs. 45-59 years; former smoker (OR, 1.46; 95% CI, 1.08-1.97; p = .014) or current smoker (OR, 1.38; 95% CI, 1.01-1.89; p = .045) vs. never smoker; and male (OR, 1.30; 95% CI, 1.01-1.68; p = .041) vs. female. Also, between increased rates of probable current/recent infection and current smoker (OR, 7.50; 95% CI, 2.32-24.31; p = .0008) or former smoker (OR, 4.07; 95% CI, 1.21-13.64; p = .023) vs. never smoker. CONCLUSIONS: Approximately 85% of the adults studied were seronegative and therefore susceptible to pertussis infection. Approximately 1% had anti-PT IgG levels indicative of current/recent pertussis infection, which could potentially be transmitted to susceptible young infants. Vaccination of adults is a key way to indirectly protect infants. TRIAL REGISTRATION: Clinical Trials.gov NCT02014519 . Prospectively registered 12 December 2013

Lightning Shielding Failure Analysis of Ultra High Voltage Power Transmission Lines

In India, the natural energy resources (thermal and hydro) are unevenly distributed and are mostly present in the remote areas and the load centers are distributed across various regions of the country. Therefore high voltage lines have become necessary for the devel-opment of large interconnected power networks and for the reliable and economic transfer of power. The increase in electric power demand due to the electric load growth has lead to the expansion of the transmission systems to ultra high voltage levels. Presently, Ultra High Voltage (UHV) power transmission lines are being built to transfer large electric power to distant load centers from the generating stations. Increasing the line voltage increases the surge impedance loading, stability and the thermal capacity of the line. Lightning is one of the major causes for the line outages and interruptions of UHV power lines. A lightning strike generates a very large voltage leading to insulator puncture, melting, burning and pitting of conductors and the supporting hardware. Lightning can lead to transient over-voltages thus leading to ash-over in the power transmission lines which are dangerous for the power equipments as well as for the human beings working in the vicinity. Ground wires are used for the protection of overhead power transmission lines against a lightning stroke. The overhead ground wires are installed such that the lightning attaches to it and shunts the lightning current to the ground through the tower, thus protecting the phase conductors. Shielding failure happens when the lightning strikes the phase conductor instead of the ground wires. Lightning shielding failure is a major con-cern in UHV lines due to their large height, very high operating voltage and wide exposure area of the phase conductors. The lightning over-voltages injected on the phase conductor (shielding failure) nally reaches the substation causing serious threat to the substation components and can lead to temporary or permanent outage of the power transmission system. There have been cases of very high shielding failure ash-overs of UHV lines and thus lightning attachment to power transmission lines need to be studied in detail to reduce the power system line outages. Several models such as electro-geometric model (EGM) and leader progression model (LPM) have been developed to study the shielding failure of power transmission lines. EGM has been extensively used to obtain lightning attachment to power transmission lines but in recent years it is seen that EGM is unable to accurately predict the lightning attach-ment to UHVAC lines. The shielding failure rates obtained by EGM does not match with the observed shielding failure rate for UHV lines. For this reason LPM is considered to obtain lightning attachment to UHV lines but LPM in its initial stage do not deal with the detailed physics of the upward leader inception, i.e., corona inception and unstable as well as stable upward leader inception from the object on the ground. In this thesis a model for the lightning attachment has been developed based on the present knowledge of the lightning physics. The thesis mainly focuses on the modelling of upward leader inception and propagation for lightning attachment to UHV power trans-mission lines. Upward leader inception is modeled based on the corona charge present near the conductor region and the upward leader propagation model is based on the correlation between the lightning induced voltage on the conductor and the voltage drop along the upward leader channel. The present model considers corona inception and modelling of unstable and stable upward leader inception from the ground object for the analysis of the lightning attachment process. The upward leader inception model developed is compared with the previous inception models and the results obtained using the present and previous models are found to be comparable. Lightning striking distances ( nal jump) for various lightning return stroke current were computed for di erent conductor heights using present lightning attachment model. It is seen that the striking distance increases with the increase in lightning re-turn stroke current and increases with increase in conductor heights. The striking distance computed using the present model matches with the value calculated using the equation proposed by the IEEE working group for the applicable conductor heights of up to 8 m. The in uence of the conductor operating voltage, cloud electric eld, lightning down-ward leader lateral distance, conductor length, transmission line tower and conductor sag on the upward lightning leader inception are analysed and reported in the thesis. It is found that the lightning attraction to power transmission line increases with increase in conductor positive operating voltage and decreases with increase in conductor negative op-erating voltage. The presence of transmission line tower reduces the lightning attachment to the conductor lines and the probability of lightning strike decreases with the increase in downward leader lateral distance from the conductor lines. The present lightning attachment model is applied to study the shielding failure of UHV power transmission lines rated for 1200 kV ac (delta and horizontal con guration) and for 800 kV dc (with and without a dedicated metallic return conductor) and thereby the lightning shielding failure ash-over rate is computed for the UHV power transmission lines. It is seen that the lightning shielding rate for UHV power transmission lines depend on the lateral distance of the downward leader channel, instantaneous 50 Hz voltage on the transmission line conductor, height of the transmission line conductor, induced voltages on the conductor and the lightning return stroke current

A Physical Model for Inception and Propagation of Upward Lightning Leader from a 1200 kV AC Power Transmission Line

UHV power transmission lines have high probability of shielding failure due to their higher height, larger exposure area and high operating voltage. Lightning upward leader inception and propagation is an integral part of lightning shielding failure analysis and need to be studied in detail. In this paper a model for lightning attachment has been proposed based on the present knowledge of lightning physics. Leader inception is modeled based on the corona charge present near the conductor region and the propagation model is based on the correlation between the lightning induced voltage on the conductor and the drop along the upward leader channel. The inception model developed is compared with previous inception models and the results obtained using the present and previous models are comparable. Lightning striking distances (final jump) for various return stroke current were computed for different conductor heights. The computed striking distance values showed good correlation with the values calculated using the equation proposed by the IEEE working group for the applicable conductor heights of up to 8 m. The model is applied to a 1200 kV AC power transmission line and inception of the upward leader is analyzed for this configuration

Diabetes and edentulism: A survey on oral health-related quality of life in Indian sub-population

Aims: The current study was conducted to assess the oral health-related quality of life in completely edentulous and diabetes mellitus (DM) patients. The null hypothesis of the survey is that there is no effect of both edentulism and diabetes on the oral health-related quality of life of patients. Settings and Design: A descriptive cross-sectional study. Methods and Materials: Test Groups: The study population was divided into three groups: • Group 1: Non-diabetic patients, wearing a complete denture. • Group 2: Diabetic patients, wearing a complete denture. • Group 3: Diabetic, completely dentulous patients. Sample Size: In total, 332 (200 males and 132 females) patients. Methodology of the Survey: Telephonic and interview methods of surveying were employed to evaluate patients. Statistical Analysis Used: The mean values, standard deviation (SD) and P value were calculated using a one-way analysis of variance (ANOVA). The level of significance was set at 5% (*P value < 0.05, ***P value < 0.001, NS: statistically non-significant). The higher the score, the higher the impact and vice-versa. Inter-group comparisons were done with post-hoc Bonferroni's test for multiple group comparisons. Results: Data collected from the survey were statistically significant, results were noted between the completely edentulous patients wearing dentures and diabetic dentulous patients. Though DM is a potent risk factor for periodontitis, leading to edentulism, statistical analysis of this study suggested that the oral health-related quality of life was affected significantly only due to edentulism and not due to DM. This is indicative of the fact that the quality of the prostheses itself determines the overall oral health-related quality of life, irrespective of whether the patient is a diabetic or not. Therefore, it can be said that the present trends of prosthodontic management of patients with DM are successfully restoring the patients physiological, psychological as well as social needs. Conclusions: Complete edentulism is the terminal outcome of a multifactorial process involving biological factors and patient-related factors. Diabetes and edentulism are both potential comorbid factors governing the oral health-related quality of life. The correlation between the two is complex and needs a thorough evaluation to improve the overall health of patients in the current clinical practice