946 research outputs found

    Tunable fibre-coupled multiphoton microscopy with a negative curvature fibre

    Get PDF
    Negative curvature fibre (NCF) guides light in its core by inhibiting the coupling of core and cladding modes. In this work, an NCF was designed and fabricated to transmit ultrashort optical pulses for multiphoton microscopy with low group velocity dispersion (GVD) at 800 nm. Its attenuation was measured to be <0.3 dB m(-1) over the range 600-850 nm and the GVD was -180 ± 70 fs(2)  m(-1) at 800 nm. Using an average fibre output power of ∼20 mW and pulse repetition rate of 80 MHz, the NCF enabled pulses with a duration of <200 fs to be transmitted through a length of 1.5 m of fibre over a tuning range of 180 nm without the need for dispersion compensation. In a 4 m fibre, temporal and spectral pulse widths were maintained to within 10% of low power values up to the maximum fibre output power achievable with the laser system used of 278 mW at 700 nm, 808 mW at 800 nm and 420 mW at 860 nm. When coupled to a multiphoton microscope, it enabled imaging of ex vivo tissue using excitation wavelengths from 740 nm to 860 nm without any need for adjustments to the set-up

    Adaptive multiphoton endomicroscopy through a dynamically deformed multicore optical fiber using proximal detection

    No full text
    This paper demonstrates multiphoton excited fluorescence imaging through a polarisation maintaining multicore fiber (PM-MCF) while the fiber is dynamically deformed using all-proximal detection. Single-shot proximal measurement of the relative optical path lengths of all the cores of the PM-MCF in double pass is achieved using a Mach-Zehnder interferometer read out by a scientific CMOS camera operating at 416 Hz. A non-linear least squares fitting procedure is then employed to determine the deformation-induced lateral shift of the excitation spot at the distal tip of the PM-MCF. An experimental validation of this approach is presented that compares the proximally measured deformation-induced lateral shift in focal spot position to an independent distally measured ground truth. The proximal measurement of deformation-induced shift in focal spot position is applied to correct for deformation-induced shifts in focal spot position during raster-scanning multiphoton excited fluorescence imaging

    The analysis of tobacco consumption in Croatia - are we successfully facing the epidemic?

    Get PDF
    Tobacco is the largest cause of morbidity and mortality. The aim of this study is to analyse several health and economically related indicators of tobacco consumption: smoking prevalence, standardized death rates (SDRs) from lung cancer and the proportion of GDP spent on tobacco in Croatia and other transitional countries - the Czech Republic, Slovakia, Poland, Hungary, Slovenia, Romania, and Bulgaria. The overall smoking prevalence in Croatia decreased by 5.2% during 1994-2005, more among females (-9.9%) than males (-0.3%). There is no significant difference in the smoking prevalence between Croatia (27.4%) and other countries. However, 33.8% of Croatian males smoked during 2002-2005, more than in Romania and the Czech Republic, and less than in Hungary and Poland. The prevalence of female smoking (21.7%) in Croatia is similar to the female smoking prevalence in Poland, the Czech Republic, and Hungary, but male smoking is predominant in all countries. The proportion of smokers among youth is above 20% and it is the highest in the Czech Republic (29.7%), followed by Hungary (26.7%), Slovenia (24.9%), Croatia (24.1%), and Poland (21.5%). The proportion of smokers among girls is higher than among boys in Slovenia, Hungary, the Czech Republic, and Croatia, contrary to Slovakia, Bulgaria, and Poland where boys smoke slightly more. There is no significant difference between the prevalence of smoking among girls in Croatia and Bulgaria, Poland, the Czech Republic, Hungary, Slovenia, and Slovakia. According to the SDR from lung cancer in males (70.3/100,000), Croatia is ranked high assuming the 3rd place, after Hungary (99.7) and Poland (72.0). With a SDR of 15.9/100,000 for females, Croatia is ranked slightly better--5th place. Tobacco consumption continues to be a major public health problem in transitional countries. Croatia conducted several campaigns and programmes in the past. However, results reveal that current anti-tobacco strategies are ineffective in reducing the smoking prevalence among men and youth. Men do not smoke less than a decade ago and, despite the observed decline among women, increasing trends are observed among teenage girls. Croatia should apply a comprehensive approach that would include raising awareness of health risks, restriction of smoking in public places, higher taxing, implementing stricter bans on advertising and promotion of tobacco as well as supporting smoking cessation. This last measure is believed to bring about some results in the medium term in targeted population groups, provided that it is supported by all health professionals. Otherwise, we may expect progress at the population level in the field of social stigmatization of smoking and wider intolerance to second-hand smoke. The full impact of smoking on the population health is yet to be seen and in the future it will undoubtedly remain one of the major contributors to the poor public health situation in Croatia

    Gender specific factors associated with having stopped smoking among in-school adolescents in Ukraine: results from the Global Youth Tobacco Survey 2005

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>The prevalence of cigarette smoking in Ukraine is different between genders and is among the highest in the world. There is need to identify gender-specific factors that are associated with having stopped smoking among adolescents.</p> <p>Findings</p> <p>We used data from the Ukraine Global Youth Tobacco Survey 2005. We carried out a backward stepwise logistic regression analysis with having stopped smoking as the outcome.</p> <p>Altogether, 2800 adolescents reported having ever smoked cigarettes. Overall 64.1% (63.4% male, and 65.5% female) adolescents reported having stopped smoking. Male adolescents who stated that smoking decreases body weight were 25% more likely, while female adolescents were 9% less likely to stop smoking. While male adolescents who received support on how to stop smoking from a family member were 7% less likely, female adolescents were 60% more likely to stop smoking. Furthermore, while male adolescents who received a lecture on the harmful effects of smoking were 10% less likely, female adolescents were 9% more likely to stop smoking. Finally both male and female adolescents who were sure or most probably that they would not smoke a cigarette offered to them by their best friends were more likely, and those adolescents who were sure that smoking is harmful to health were less likely to stop smoking.</p> <p>Conclusions</p> <p>Our study has identified some factors that are associated with having quit smoking that are gender-specific. We believe public health programs targeting adolescent smoking should consider these factors in their design and implementation of gender sensitive interventions.</p

    Oneida nation of New York: health needs assessment 1990

    Get PDF
    This is the report of a health needs assessment for the Oneida Indian Nation of New York (ONNY). This needs assessment was conducted in order to collect population-based data related to behavioral risks and reproductive health for Oneida males and females. The survey of the Oneida was initiated because there is almost no risk factor data available on Indian tribes of the northeast, and none available for the Oneida Nation of New York. There are four primary goals for the 1990 Oneida Nation Health Needs Assessment. They are 1) to collect behavioral risk factor and reproductive health data for adult Oneida Nation members living on or near Oneida Nation lands, 2) to assess the current basic health needs of the ONNY, 3) to document the medical providers and hospitals which are currently being utilized by the Nation members and. 4) to develop recommendations for use by health planners from this baseline data.The Oneida Nation Health Needs Assessment (ONHNA) was carried out among enrolled members of the Oneida Nation who were 18 years of age and older who lived in the six counties that are contiguous to the Oneida Nation lands. The Nation Enrollment List was used to identify the Oneida population located in the six-county area. The choice to interview only adults was made to avoid legal difficulties in interviewing minors. Interviewing was conducted in each household face-to-face rather than using mailed questionnaires or telephone contact. All interviewers were enrolled Oneida Nation members. Interviews were conducted by interviewers of the same sex as the respondent. All interviewers participated in one week of training prior to the start of the field work. Four types of data were collected. First, the behavioral risk factors surveyed were related to the 10 leading causes of death in the United States. Behavioral factors include seat belt usage, physical exercise, diet, cigarette and smokeless tobacco usage, alcohol consumption, and the existence of high blood pressure. The second data set included health needs. The survey questions dealt with the prevalence of current diseases and health problems among the Oneidas, and with whether the Oneida people have routine screening tests such as cholesterol, diabetes, and hypertension, and eye exams, pap smears, breast exams, and rectal exams. The third set of data questions focused on reproductive health factors. Questions covered topics such as fertility, contraception, and general maternal-child health conditions. The fourth and final set of questions gathered data on health care utilization. This data will be used to establish health provider contracts with physicians, dentists, pediatricians, and hospitals to provide quality health care for a more reasonable cost. For each risk factor, comparisons were made between the Oneida Nation and data from the 1988 New York State Behavioral Risk Factor Survey.The individual completion rates were 54% for females and 69% for males for a total of 211 respondents in all. The following is an abbreviated summary of selected data from the survey. Seat belt use was only slightly lower than for all New Yorkers. Non-use was highest among young drivers. Sixty percent of Oneida males and 78 percent of Oneida females reported having their blood pressure taken within a year of the survey. All Oneida members were more active physically than the general New York population. However, all Oneida members were more likely to be overweight by comparison Forty percent of all Oneida people are smokers compared to 25 percent of the New York population. Fifty-seven percent of Oneida males and 32 percent of Oneida females are classified as acute and heavy drinkers. Percentages for regular health checks across all factors vary considerably among the Oneida people. Several areas of concern were identified including cholesterol checks, diabetes screening, rectal exams and mammograms. The completed fertility of the Oneida women in this survey is 2.1 children which is lower than that of all U.S. women surveyed in the 1980 census. Female sterilization is the most prevalent contraceptive method among Oneida women. as it is among the general U.S. population.With respect to behavioral risks, cigarette smoking and alcohol consumption are of major concern. This impacts on concerns for overall reproductive health. The task now is to identify the highest priority objectives and to secure resources needed to accomplish these tasks

    Clustering of smoking, alcohol drinking and cannabis use in adolescents in a rapidly developing country

    Get PDF
    BACKGROUND: Smoking, alcohol drinking and cannabis use ("risk behaviors") are often initiated at a young age but few epidemiological studies have assessed their joined prevalence in children in developing countries. This study aims at examining the joint prevalence of these behaviors in adolescents in the Seychelles, a rapidly developing country in the Indian Ocean. METHODS: Cross-sectional survey in a representative sample of secondary school students using an anonymous self-administered questionnaire (Global Youth Tobacco Survey). The questionnaire was completed by 1,321 (92%) of 1,442 eligible students aged 11 to 17 years. Main variables of interest included smoking cigarettes on ≥1 day in the past 30 days; drinking any alcohol beverage on ≥1 day in the past 30 days and using cannabis at least once in the past 12 months. RESULTS: In boys and girls, respectively, prevalence (95% CI) was 30% (26–34)/21% (18–25) for smoking, 49% (45–54)/48% (43–52) for drinking, and 17% (15–20)/8% (6–10) for cannabis use. The prevalence of all these behaviors increased with age. Smokers were two times more likely than non-smokers to drink and nine times more likely to use cannabis. Drinkers were three times more likely than non-drinkers to smoke or to use cannabis. Comparison of observed versus expected frequencies of combination categories demonstrated clustering of these risk behaviors in students (P < 0.001). CONCLUSION: Smoking, drinking and cannabis use were common and clustered among adolescents of a rapidly developing country. These findings stress the need for early and integrated prevention programs

    Evaluation of the use of Global Youth Tobacco Survey (GYTS) data for developing evidence-based tobacco control policies in Turkey

    Get PDF
    Introduction The tobacco control effort in Turkey has made significant progress in recent years. Turkey initiated its tobacco control effort with the passing of Law 4207 (The Prevention of Harmful Effects of Tobacco Products) in 1996 and ratified the World Health Organization (WHO) Framework Convention on Tobacco Control (FCTC) in 2004. It is important to base policy decisions on valid and reliable evidence from population-based, representative studies that are periodically repeated to enable policy makers to monitor the results of their interventions and to appropriately tailor anti-tobacco activities towards future needs. Methods The Global Youth Tobacco Survey (GYTS) was developed to track tobacco use among young people and enhance the capacity of countries to design, implement, and evaluate tobacco control and prevention programs. Turkey conducted the GYTS in 2003 and data from this survey can be used as baseline measures for evaluation of the tobacco control programs implemented by the Ministry of Health (MOH) of the Turkish government. Results The GYTS was conducted in 2003 on a representative sample of students aged 13 to 15 years. It indicated that almost 3 in 10 students in Turkey had ever smoked cigarettes, with significantly higher rates among boys. Current cigarette smoking rates were lower, at 9% for boys and 4% for girls. The prevalence of current use of other tobacco products was about half these figures for each gender. About 80% were exposed to secondhand smoke. Exposure to pro-smoking media messages was not rare. Almost half of the smokers 'usually' bought their tobacco from a store, despite the law prohibiting this. Exposure to teaching against smoking in schools was not universal. Conclusion Findings from the GYTS, with periodic repeats of the survey, can be used to monitor the impact of enforcing various provisions of the present law (No: 4207), the progress made in achieving the goals of the WHO FCTC, and the effectiveness of various preventive interventions against smoking. Such data would inform and help in the development of public health strategy.PubMedWoSScopu

    Tobacco use among students aged 13–15 years in Greece: the GYTS project

    Get PDF
    BACKGROUND: Data on the prevalence of tobacco use among teenagers in Greece are limited. We examined the prevalence of smoking among middle-school students in Greece using the Global Youth Tobacco Survey (GYTS). METHODS: The Global Youth Tobacco Survey was implemented in Greece during the academic year 2004 – 2005 by the University of Thessaly and the National School of Public Health. Data were collected using the GYTS self-administered anonymous questionnaire, which was distributed by specifically trained field workers to a nationally representative sample of middle-school students aged 13–15 years (through randomly selected schools and classes), randomly selected through a two-stage cluster sample design. Data processing and statistical analyses were performed at the Centers for Disease Control and Prevention (CDC). RESULTS: About one third of the students 32.1% (29.4 – 35.0) reported that they had tried tobacco in the past, while 16.2% (14.3 – 18.4) reported being current users of tobacco products. In addition, 1 in 4 of ever smokers reported that they began smoking before the age of 10 years old. Almost 1 in 5 never smokers reported being susceptible to initiate smoking in the next year and about 89.8% (88.3 – 91.1) of the respondents were exposed to environmental tobacco smoke in their homes and 94.1% (93.2 – 94.9) in public places. Finally, a strikingly high number of students 95% (89.5 – 97.7) reported that they were able to buy their own cigarettes without restrictions. CONCLUSION: The results of the GYTS show that the prevalence of smoking in middle-school children is alarmingly high in Greece. Smoking among young people constitutes a significant problem that is destined to worsen in the absence of any comprehensive efforts focused on strict anti-smoking legislation, policies and tobacco control interventions targeting children at a young age

    Perceptions of anti-smoking messages amongst high school students in Pakistan

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Surveys have provided evidence that tobacco use is widely prevalent amongst the youth in Pakistan. Several reviews have evaluated the effectiveness of various tobacco control programs, however, few have taken into account the perceptions of students themselves regarding these measures. The aim of this study was to determine the most effective anti-smoking messages that can be delivered to high-school students in Pakistan, based on their self-rated perceptions. It also aimed to assess the impact of pictorial/multi-media messages compared with written health warnings and to discover differences in perceptions of smokers to those of non-smokers to health warning messages.</p> <p>Methods</p> <p>This study was carried out in five major cities of Pakistan in private English-medium schools. A presentation was delivered at each school that highlighted the well-established health consequences of smoking using both written health warnings and pictorial/multi-media health messages. Following the presentation, the participants filled out a graded questionnaire form, using which they rated the risk-factors and messages that they thought were most effective in stopping or preventing them from smoking. The Friedman test was used to rank responses to each of the questions in the form. The Wilcoxon Signed Rank test used to analyze the impact of pictorial/multi-media messages over written statements. The Mann Whitney U test was used to compare responses of smokers with those of non-smokers.</p> <p>Results</p> <p>Picture of an oral cavity cancer, videos of a cancer patient using an electronic voice box and a patient on a ventilator, were perceived to be the most effective anti-smoking messages by students. Addiction, harming others through passive smoking and impact of smoking on disposable incomes were perceived to be less effective messages. Pictorial/multi-media messages were perceived to be more effective than written health warnings. Health warnings were perceived as less effective amongst smokers compared to non-smokers.</p> <p>Conclusion</p> <p>Graphic pictorial/multi-media health warnings that depict cosmetic and functional distortions were perceived as effective anti-smoking messages by English-medium high school students in Pakistan. Smokers demonstrated greater resistance to health promotion messages compared with non-smokers. Targeted interventions for high school students may be beneficial.</p
    corecore