Characterization of Tunable Micro-Lenses with a Versatile Optical Measuring System

In this work, we present the results of the opto⁻electro⁻mechanical characterization of tunable micro-lenses, Tlens®, performed with a single-spot optical measuring system. Tested devices are composed of a transparent soft polymer layer that is deposited on a supporting glass substrate and is covered by a glass membrane with a thin-film piezoelectric actuator on top. Near-infrared optical low-coherence reflectometry is exploited for both static and low-frequency dynamic analyses in the time domain. Optical thickness of the layers and of the overall structure, actuation efficiency, and hysteretic behavior of the piezo-actuator as a function of driving voltage are obtained by processing the back-reflected signal in different ways. The use of optical sources with relatively short coherence lengths allows performing interferometric measurements without spurious resonance effects due to multiple parallel interfaces, furthermore, selecting the plane/layer to be monitored. We finally report results of direct measurements of Tlens® optical power as a function of driving voltage, performed by redirecting a He-Ne laser beam on the lens and monitoring the focused spot at various distances with a digital camera.

[Factors associated with alcohol consumption in the youth of the province of Brescia]

We investigated factors related to adolescent alcohol consumption by administering an anonymous questionnaire to 2737 9th and 13th grade high-school students in the province of Brescia. A total of 1364 students coming from an urban area (the town of Brescia with about 200,000 inhabitants) and 1373 students from a mountainous area (Breno, Local Health Unit N. 37 in the Lombardy Region with 83,000 inhabitants) were interviewed. The associations between alcohol drinking and some demographic, socio-economic, behavioural and environmental variables were assessed by computing the correspective odds ratios (OR) by fitting logistic regression models for ordinal response variables ("cumulative odds" models). The results showed that the following variables were positively associated with alcohol consumption: 1) residence in a mountainous area, especially as regards spirits consumption; 2) experimental and regular smoking; 3) peer alcohol drinking (best friend and partner). Parents' daily alcohol consumption was associated with wine drinking, but not with either spirits consumption or frequency of drunkenness among students. A slight inverse relationship was also found between students' alcohol intake and their knowledge of the health hazards of alcohol, but it was not significant for all groups of students.

Factors associated with non-participation of women in a breast cancer screening programme in a town in northern Italy

STUDY OBJECTIVE

The aim was to investigate the reasons for the high percentage of women refusing to attend a breast cancer screening programme in the Health District of Brescia, Italy.

DESIGN

This was a survey of a sample of non-attenders to the programme, who were interviewed using a structured questionnaire.

SETTING

Non-attenders all lived in a central area of the town near the screening centre.

PARTICIPANTS

Of the 612 non-attenders eligible for interview, 183 could not be interviewed: one had died, 86 were away from home at two different visits, 32 were no longer resident at the known address, eight had serious health problems, 17 had undergone mastectomy, and 39 refused the interview. Overall, a total of 429 of the 612 eligible women were interviewed (70.1%).

MEASUREMENTS AND MAIN RESULTS

Attenders and non-attenders were compared with respect to demographic and socioeconomic factors, use of preventive medicine, and prevalence of risk factors for breast cancer. The response was higher among less educated women, married and widowed women, and those born in the province than among more educated, single or divorced, and immigrant women. Most of the women interviewed gave practical reasons for non-participation, but lack of interest/distrust and fear/worry/anxiety also seemed important. The number of non-attenders who had had a Papanicolaou test within the previous three years was three times higher than those who had had mammography, suggesting that non-attenders were more interested in types of preventive medicine other than screening for breast cancer by mammography. Attenders and non-attenders appeared similar as regards distribution of conventional breast cancer risk factors.

CONCLUSIONS

Greater effort in the information campaign might increase the participation rate in screening for breast cancer, although to a lesser extent than expected: if non-attenders potentially recruitable in our screening were added to attenders, overall compliance of the programme was about 75%, lower than that observed in some programmes in northern Europe.