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The number of global tobacco-related deaths is projected to increase from about 6 million to 8 million annually by 2030, with more than 80% of these occurring in low- and middle-income countries (LMICs). The World Health Organization Framework Convention on Tobacco Control (FCTC) came into force in 2005 and Article 14 relates specifically to the treatment of tobacco dependence. However, LMICs, in particular, face several barriers to implementing tobacco dependence treatment. This paper is a descriptive evaluation of a novel grant funding mechanism that was initiated in 2014 to address these barriers. Global Bridges. Healthcare Alliance for Tobacco Dependence Treatment aims to create and mobilize a global network of healthcare professionals and organizations dedicated to advancing evidence-based tobacco dependence treatment and advocating for effective tobacco control policy. A 2014 request for proposals (RFP) focused on these goals, particularly in LMICs, where funding for this work had been previously unavailable. 19 grants were awarded by Global Bridges to organizations in low- and middle-income countries across all six WHO regions. Virtually all focused on developing a tobacco dependence treatment curriculum for healthcare providers, while also influencing the political environment for Article 14 implementation. As a direct result of these projects, close to 9,000 healthcare providers have been trained in tobacco dependence treatment and an estimated 150,000 patients have been offered treatment. Because most of these projects are designed with a “train-the-trainer” component, two years of grant funding has been a tremendous catalyst for accelerating change in tobacco dependence treatment practices throughout the world. In order to foster such exponential growth and continue to maintain the impact of these projects, ongoing financial, educational, and professional commitments are required.

The Framework Convention on Tobacco Control (FCTC) set standards for global tobacco control, including the implementation of evidence-based tobacco dependence treatment. However, efforts to implement tobacco treatment programmes globally have been few. In order to expand tobacco treatment expertise and programmes, a new network called Global Bridges (GB) was established. This network provided training in tobacco treatment and opportunities to share best practices on implementation of tobacco dependence treatment and training programmes. In this analysis of the GB network, we found that 75% of the network members attended trainings, 60% disseminated knowledge gained through GB training, and network centralization was high (0.85). These results demonstrate initial success in network implementation, and create a foundation for expanded focus on tobacco treatment globally.

Introduction: Global Bridges, hosted at Mayo Clinic since 2010, is the only international network of healthcare professionals dedicated to tobacco dependence treatment. Globally, fewer resources have been dedicated to treatment than to other evidence-based tobacco control policies. The Global Bridges network seeks to aid in filling this gap in tobacco control.Aims: This paper identifies ways to advance tobacco dependence treatment, as well as tobacco control, through efficient and effective use of a global health care provider network.Methods: Observation and critical analysis of lessons learned, project outcomes to date, and network analysis.Results/Findings: The initiative has built a strong global foundation, with training curricula developed and delivered in a number of countries, including low- and middle-income countries. While basic evaluation of content mastery and learner satisfaction has been conducted, more intensive evaluation and follow-up to confirm public health impact are essential needs. Finally, program analysis and application of management theory can be used in aiding future activities aimed at providing support for health care providers in the delivery of tobacco dependence treatment and in similar global public health endeavors.Conclusions: The Global Bridges healthcare professional network, now in its sixth year, has developed training curricula and expanded evidence-based tobacco dependence education among healthcare professionals. Global Bridges comprises a unique and important component of the broader tobacco control community, and can play an integral role in furthering global tobacco control progress.

group of experts began more than 18 months earlier to assess the science related to tobacco use and its effect on humans. The group came to the conclusion that cigarette smoking causes lung cancer and laryngeal cancer. The report also noted that there was suggestive evidence, if not definitive proof, of a causative role of smoking in other illnesses such as emphysema, cardiovascular disease, and various types of cancer. The conclusions reached by this report are arguably the most important and far-reaching in the history of public health and are, perhaps, the classic example of science driving public policy. It gave extraordinary momentum to the tobacco control movement and caused public opinion and behavior to change considerably, even though a large part of the population was not initially predisposed to accept the message. At the time, cigarette smoking was a significant part of America’s culture and the tobacco industry was a significant part of the US economy. In surveys, 52% of American men and 35% of American women were active cigarette smokers. The United States grew, manufactured, and exported more tobacco than any other country. In 1960, tobacco contributed $15 billion in wages to some 660,000 American workers. 2,3 Given the numerous medical controversies today, it is of value to explore why this process was so successful and why so many were willing to accept this pronouncement as truth. The findings of the 1964 Surgeon General’s report were not the first pronouncement that tobacco use was harmful. In the 7 years prior, there had been at least 2 previous statements from the previous Surgeon General and several announcements from expert consensus panels in the United States and abroad. The process used to establish and run the group set a precedent for dealing with and interpreting controversial medical and scientific issues. A group of learned individuals was brought together to review the science as a type of grand jury. A critical criterion for committee membership was being capable of reaching beyond one’s own discipline to learn about and consider complex data. The process also set a standard for choosing scholarly individuals who have no financial or emotional conflicts of interest to consider a highly charged controversial issue. They would review more than 7000 papers and intensively study more than 27 case-control and cohort studies and 7 broader cohort studies in order to reach their then-momentous conclusions.

Adiabatic bend transitions in large mode area multimode fibres were investigated theoretically using the beam propagation method. Adiabatic bend transducers preserve the power of guided light in the fundamental mode while guiding from one level of curvature to another for improved operation of mode filters and fibre amplifiers. A method is shown and used to find the optimised guidance path. Applications of these transducers include modal power back-converters, and guidance paths into and out of higher order mode filtering devices which work on bending.

Surface modification as a route to improving the performance of polymeric biomaterials is an area of much topical interest. Ultraviolet (UV) light treatment has received much attention, but polymers so treated revert to their original surface condition over a period of time—an effect known as hydrophobic recovery. It is important to develop an understanding of the underlying processes contributing to the effect, since it has an impact on the applicability of UV treatment. In this work a number of polymeric biomaterials were surface-modified using 172 nm UV light from an excimer lamp. The modified polymers were characterised using contact angle, surface free energy (SFE) measurements and X-Ray Photoelectron Spectroscopy (XPS) techniques. The wettability, variation in surface free energy and chemical functionality changes were analysed on the surfaces immediately after UV treatment and subsequently over a period of 28 days. It was noted that hydrophobic recovery proceeds at a different rate for each polymer, is generally a two-phase process and that surfaces are still more hydrophilic after 28 days than the original untreated state. XPS analysis reveals that particular chemical configurations move from the surface at a faster rate than others which may contribute to the two-phase nature of the process.

Characterisation of the plasma plume induced by femtosecond laser–metal interactions has been carried out using a Langmuir probe. A double peak distribution of ablated ions and electrons has been recorded during time of flight (TOF) experiments for three metals studied (Ag, Cu and Ni). The first peak which occurs earliest in time is attributed to a surface layer of contaminants on the metal surface as it is shown to disappear after several laser shots. The re-growth of this peak, thought to be due to a recontamination process on the surface of the metal, is the subject of this paper. Two re-contamination mechanisms were considered; adsorption of contaminants from the ambient gas, and surface diffusion effects from the surrounding contaminants. Re-contamination rates for Ag, Cu and Ni were studied under two distinct gas pressures to investigate the contamination effects from the ambient. Effects arising from surface diffusion were investigated by raising the temperature of the metal sample to increase the surface mobility of the contaminants. The total contribution of contamination species present in the ablation plume was estimated by conducting angular distribution measurements of the plume. Surface diffusion of the surrounding contaminants was found to be the dominant recontamination process.

The physical mechanisms responsible for the formation of nanobump structures on a surface of a thin metal film irradiated by a tightly focused femtosecond laser pulse are investigated in a large-scale molecular dynamics simulation. The simulation is performed with a combined atomistic-continuum model adapted for an adequate representation of laser-induced processes at the length-scale of the entire laser spot. The relaxation of the compressive stresses generated by the fast laser heating is identified as the main driving force responsible for the separation of the metal film from the substrate and formation of the nanobump. The kinetics of the transient melting and resolidification, occurring under conditions of the fast cooling due to the two-dimensional electron heat conduction, defines the shape of the nanobump. The predictions of the simulation are related to the surface structures observed in femtosecond laser nanostructuring.

Expansion of the laser plume from a silicon wafer into surrounding gas is considered in the range of ambient gas pressure from 0.1 to 1 bar using a kinetic approach. The plume is generated by a nanosecond Gaussian laser pulse. Absorption of laser radiation and heating and melting of the target are described by a two-dimensional thermal model. Axisymmetric flow in the laser plume is calculated by the direct simulation Monte Carlo method. It was found that diffusion of mixture components is significant in the considered time scale, flow is non-equilibrium, and regions of high rarefaction temporally appear in the flow. In atmospheric pressure, the re-deposition of the silicon vapor was observed only in the vicinity of the laser spot.

A flexible workstation equipped with a solid state laser operating at 266 nm wavelength was used to machine holes in polyethylene terephthalate, polyimide and polycarbonate. An optical pulse picker was employed to reduce the high repetition rates of the laser, while a breakthrough sensor was used to avoid over-drilling of through holes. For each material, different repetition rates and designed pulse trains were tested to improve feature quality and process efficiency. Although the three polymers had very different reactions at this wavelength they all showed an improvement in feature quality with decreasing repetition rate due to a reduction in thermal effects. Up to 10 kHz the average depth per pulse remained unchanged and afterwards a slight increase was observed but this was accompanied by large uncertainties. Bursts of pulses at 40 kHz inserted inside the low repetition rate pulse train reduced the drilling time and the amount of debris redeposited without affecting the feature quality. It was found that a number of cleaning pulses after perforation eliminates the heat affected zone around exits. Holes with entrance diameters below 20 μm and exit diameters as small as 2 μm were obtained with high repeatability.

The relationship between focused spot size, pulse energy, and ablated hole diameter was explored using 266 nm nanosecond pulses and 775 nm femtosecond pulses on polyethylene terephthalate. The spot size of a Gaussian laser beam can be deduced from the diameters of holes machined with single shots at different pulse energies but the results can be influenced by such issues as the thickness of the material and the range of fluence chosen. These limitations of the method were investigated. Multiple shot craters were also measured but gave an overestimation of spot size, particularly in the femtosecond case. A model was developed to predict the diameter for a given energy and number of shots. Tests of the model gave results that agreed well with the predicted values. It was found that for the same total energy smaller holes can be obtained by decreasing the pulse energy and increasing the number of shots. An effective spot size for multiple shots was determined.

A time resolving Langmuir probe was used to study the plasma plumes produced by the ablation of Ag, Ni and Al targets with laser pulses of different pulse durations (0.2 − 10 ps). These metals were chosen because their electron-phonon relaxation times, τe-ph, are of the order of the pulse durations used. The time of flight (TOF) signals have been used to establish the threshold fluences and plume expansion dynamics of the laser produced plasmas for the different pulse durations. The angular dependence of the magnitude of the ion flux was analysed on the basis of Anisimov's self-similar model of the plasma expansion. The amount of charge in the ablation plume is compared for the different pulse durations.

Jordan, a high tobacco-burden country, has been working to expand its tobacco dependence treatment services and has completed development of its first customized treatment guidelines. Our paper presents the development process for these guidelines. A group of national and international experts was formed and a national situation analysis for tobacco dependence treatment practices and a detailed review of international evidence were conducted. The guidelines were then drafted and reviewed by national, regional and international experts and were official endorsed by the Jordanian Ministry of Health before being launched. The guidelines comprise concise descriptions and practical supplementary flowcharts covering the major elements of general tobacco dependence treatment. These are the first comprehensive Arabic-language guidelines, including a section focusing on waterpipe use, and we believe they are a reliable and useful resource for neighbouring countries seeking to develop similar guidelines.الأساس المنطقي وإعداد الدلائل الإرشادية الأردنية لمعالجة إدمان التبغ.هبة أيوب، نورعبيدات، سكوت لايشو، توم جلين، فراس هواري.إن الأردن - البلد الذي لديه عبء تبغ مرتفع - كان يعمل عى توسيع الخدمات التي يقدمها لمعالجة الاعتاد عى التبغ، وقد انتهى من وضع أولى دلائله الإرشادية المصممة خصيصاً لهذه المعالجة. إن بحثنا هذا تعرض لعملية إعداد هذه الدلائل الإرشادية. فقد شُكِّل فريق من خراء وطنين ودولين، وأجري تحليل للوضع الوطني فيا يتعلق بممارسات معالجة الاعتاد عى التبغ، واستعراض مفصل للأدلة الدولية. ثم تمت صياغة الدلائل الإرشادية وراجعها خراء وطنيون وإقليميون ودوليون، وأقرت رسمياً من قبل وزارة الصحة الأردنية قبل إطلاقها. وتتألف الدلائل الإرشادية من توصيفات موجزة ومخططات تكميلية عملية تغطي العناصر الرئيسية لمعالجة الاعتاد عى التبغ بشكل عام. هذه هي أولى الدلائل الإرشادية الشاملة باللغة العربية، وهي تتضمن قساً يركز عى تعاطي الشيشة، ونعتقد أنها مصدر موثوق ومفيد لدول الجوار التي تسعى إلى وضع دلائل إرشادية مشابهة.Recommandations pour le traitement de la dépendance au tabac en Jordanie : argumentation et développement.La Jordanie, un pays ayant une forte charge tabagique, a oeuvré pour développer ses services de traitement de la dépendance au tabac et a terminé l’élaboration de ses premières recommandations thérapeutiques personnalisées. Notre article présente le processus de développement de ces recommandations. Un groupe d’experts nationaux et internationaux a été créé et une analyse de la situation nationale en matière de pratiques pour le traitement de la dépendance au tabac ainsi qu’un examen détaillé des preuves internationales ont été menés. Un projet de directives a ensuite été rédigé puis examiné par des experts nationaux, régionaux et internationaux et a été officiellement adopté par le ministère de la Santé jordanien avant son lancement. Les directives incluent des descriptions concises et des schémas pratiques supplémentaires couvrant les principaux éléments du traitement général de la dépendance au tabac. Il s’agit des premières recommandations exhaustives en langue arabe comprenant une partie axée sur l’utilisation de la pipe à eau, et nous pensons qu’elles représentent une ressource fiable et utile pour les pays voisins cherchant à élaborer des recommandations similaires.

We report a study of femtosecond laser pulse absorption of wafer grade silicon with an average pulse duration of 150 fs, centred on a wavelength of 775 nm. The electrical response of the laser excited carriers, over a range of fluences up to the ablation threshold for silicon is analysed. The silicon used for the experiments is a uniformly doped P -type wafer with a concentration of 1 × 10 12 cm −3 throughout its volume. The purpose of this work is to use the electrical properties of the excited carriers as a method for analysing the interaction between femtosecond pulses and the silicon lattice below the ablation threshold, and to determine the evolution of the excited carriers after the femtosecond pulse is absorbed in silicon. This paper uses simulation software to solve the ambipolar continuity equation for the evolution of the excited carrier group given the initial values and boundary conditions of the experimental system. The paper derives results for the total number of excited carriers created as a function of laser fluence, in addition to the bulk excited carrier dynamics and lifetime after femtosecond laser excitation. Based on the results for the total number of excited carriers as a function of the average laser fluence, a value of 0.09 J cm −2 is measured as the fluence where lattice defects started to reduce the effective quantity of carriers that could be detected and hence indicated incubation lattice damage.

This work reports on the structural changes that take place in wafer grade silicon when it is micro-machined with ultra-short laser pulses of 150 fs duration. A Chirped Pulse Amplification (CPA) Ti:Sapphire laser was used, with an operating wavelength centered on 775 nm and a maximum repetition rate of 1 KHz. The laser induced damage was characterized over the fluence range 0.43–14 J cm-2, and for each fluence a progressively increasing number of pulses was used. The analytical tools used to characterize the samples were all based upon electron microscopy. A 30 KeV scanning transmission electron microscope (STEM) imaging technique was developed to observe defects in the crystal lattice and the thermal-mechanical damage in the area surrounding the laser machined region. Mechanical cross sectioning (in conjunction with Scanning Electron Microscope (SEM) surface imaging) was also used to reveal the internal structure, composition, and dimensions of the laser machined structures. Based on this analysis, it will be shown that laser machining of silicon with femtosecond pulses can produce features with minimal thermal damage, although lattice damage created by mechanical stresses and the deposition of ablated material both limit the extent to which this can be achieved, particularly with high aspect ratios. A key feature of the work presented here is the high-resolution STEM images of the laser-machined structures.

Detailed studies on the ablation of metal targets in air with femtosecond laser pulses are reported. The laser pulses used for the study were 775 nm in wavelength, 150 fs in pulse duration, and the repetition rate used was 100 Hz. Ablation thresholds of copper, titanium, niobium, and stainless steel are measured. The ablation threshold fluence depends on the number of pulses applied to the same spot. The strength of this dependence is governed by the incubation coefficient, S , which has been determined along with the single-shot ablation threshold, φ th (1), for all the metals studied. The accumulation behaviour results from the build-up of plastic deformation induced by the laser pulses. Two distinct ablation phases have been identified from ablation rate curves and an SEM investigation of the ablated morphologies. Ripples were observed on the material surface during the gentle ablation phase, whereas much rougher structures occurred during the stronger ablation phase. Morphological changes of the ablated regions were studied as a function of fluence and incident laser shot number. The observed morphologies seem to suggest that normal vaporisation and phase explosion are the most probable physical mechanisms responsible for material removal during ablation.

The work described in this paper characterises the laser ablation of wafer grade silicon, using both a Gaussian beam and the reconstructed wavefront of a femtosecond laser. The reconstructed wavefront was produced by transmission through a computer generated hologram (CGH). The laser used was a chirped pulsed amplification (CPA), Ti:sapphire system, operating at a centre wavelength of 775 nm, and with a average pulse duration of 150 fs. The dependence of the size of the ablated region on the number of pulses, used over a range of fluences, enabled the ablation threshold as a function of the number of pulses to be determined, for different beam profiles. With the Gaussian profile of the femtosecond laser, it was observed that the ablation threshold for silicon changes with the number of pulses used. The ablation threshold for a single laser pulse was determined as 0.45 J cm −2 as compared to 0.18 J cm −2 for 20 laser pulses. This behaviour can be attributed to the incubation parameter for silicon, which was estimated to be 0.7. In high resolution scanning electron microscope (SEM) images of the silicon surface, it was possible to observe the progression of the ablated area, within the Gaussian profile of the laser, from surface features such as circular ripples, machined with 2 laser pulses at the centre of the beam, to larger diameter laser holes, machined with 20 laser pulses. To improve the lateral precision of the ablated region over a range of pulses and fluences, a CGH was designed and constructed to transform the Gaussian profile of the laser beam into a more uniform fluence distribution. The reconstructed wavefronts produced from different CGH transmission structures were evaluated and the most successful was used to demonstrate improved laser machining of silicon. It was observed that the reconstructed beam was not Gaussian and that the ablated holes converged to a constant diameter with higher pulse fluences and pulse numbers.

Understanding culture is an essential key to reducing tobacco use. Conceptualizations of culture vary across scientific disciplines and theoretical orientations. Because of the complexity of the causes and effects of tobacco use, no single discipline has sufficient capacity to undertake a comprehensive approach to studying culture and tobacco. Transdisciplinary research offers a means of bridging disciplinary perspectives. This paper reviews epidemiological data on observed variation in smoking patterns across national groups, ethnicities and genders, and presents reasons for studying culture in tobacco control research. We discuss and contrast conceptualizations and specific definitions of culture and identify aspects of each conceptualization that are relevant to research on tobacco. We present a multilevel, multidimensional conceptual framework for transdisciplinary research teams to use to think together about the influence of culture on tobacco and of tobacco on culture. The framework challenges researchers to think about how the sociocultural context influences tobacco use at micro, meso, and macro levels. Finally, we offer suggestions for improving transdisciplinary research on culture and tobacco.

We present power and temperature dependent photoluminescence measurement of two types of InP/GaInP self-assembled quantum dots. In order to investigate the relaxation and recombination mechanism in these structures, time resolved measurements were performed. The behaviour of the decay times as a function of power and temperature can be explained as type II quantum dot behaviour. To examine the properties of a single quantum dot we have structured the samples with mesas of different sizes to reduce the amount of optically active dots. The photoluminescence results of these experiments are also discussed here.

Self-assembled type A GaxIn1–xP/Ga0.5In0.5P quantum dots (QDs) have been investigated using continuous wave and time-resolved photoluminescence (PL) techniques. The QDs were grown by low-pressure metal-organic vapour phase epitaxy using the Stranski–Krastanow growth mode. A substrate misorientation of 15� towards the (111)B plane leads to the formation of type A dots with a height of approximately 5 nm. The novel effect of varying the Ga content of the QDs has been examined and the PL emission energy of the dots is observed to increase from 1.71 eV to 1.90 eV as the Ga content is varied from 0% to 30%. Temperature dependent (5 K to 260 K) time-resolved PL measurements have also been performed in order to study the dot carrier dynamics in more detail. These measurements indicate that the Type II InP/GaInP QDs either become smaller or that the band structure changes to a Type I alignment with the addition of Ga. Both effects, if present, could be attributed to a decrease in the dot strain as Ga is added.

The capped self-assembled Ga x In 1− x P/GaP quantum dots grown by low-pressure metalorganic vapour phase epitaxy on selenium doped GaP substrates have been investigated by continuous wave (CW) and time resolved photoluminescence (PL). The dependence of the dot PL with respect to varying growth temperature and gallium composition has been examined and compared with atomic force microscopy results obtained on similar uncapped samples. Surprisingly, the results indicate that the optical characteristics of the dots are almost independent of the sample growth temperature and nominal gallium content. This result is thought to be due to the fact that the islands undergo a phase separation process forming In-rich dots surrounded by Ga-rich base layers. Temperature dependent continuous wave (CW) PL measurements, as well as temperature dependent and excitation power density dependent, time resolved PL experiments have been performed and support this hypothesis.

Background Considerable effort has been expended on tobacco control strategies in the United States since the mid-1950s. However, we have little quantitative information on how changes in smoking behaviors have impacted lung cancer mortality. We quantified the cumulative impact of changes in smoking behaviors that started in the mid-1950s on lung cancer mortality in the United States over the period 1975–2000. Methods A consortium of six groups of investigators used common inputs consisting of simulated cohort-wise smoking histories for the birth cohorts of 1890 through 1970 and independent models to estimate the number of US lung cancer deaths averted during 1975–2000 as a result of changes in smoking behavior that began in the mid-1950s. We also estimated the number of deaths that could have been averted had tobacco control been completely effective in eliminating smoking after the Surgeon General’s first report on Smoking and Health in 1964. Results Approximately 795 851 US lung cancer deaths were averted during the period 1975–2000: 552 574 among men and 243 277 among women. In the year 2000 alone, approximately 70 218 lung cancer deaths were averted: 44 135 among men and 26 083 among women. However, these numbers are estimated to represent approximately 32% of lung cancer deaths that could have potentially been averted during the period 1975–2000, 38% of the lung cancer deaths that could have been averted in 1991–2000, and 44% of lung cancer deaths that could have been averted in 2000. Conclusions Our results reflect the cumulative impact of changes in smoking behavior since the 1950s. Despite a large impact of changing smoking behaviors on lung cancer deaths, lung cancer remains a major public health problem. Continued efforts at tobacco control are critical to further reduce the burden of this disease.

The average fluorescence lifetimes of nine North Sea crude oils with API gravities of between 20 and 51 were measured using a modular, filter based, instrument developed in-house. Two pulsed light emitting diode (LED) excitation sources (460 and 510 nm) were used to excite fluorescence, the lifetime of which was measured at a range of emission wavelengths. Fluorescence lifetimes were found to vary from 1.8 to 8.2 ns with confidence intervals of ±0.11 ns. The average lifetimes at all emission wavelengths were linearly correlated with API gravity and with aromatic concentration with the best results being obtained with the 460 nm excitation source. Predictive models with an accuracy of ±7.6 API degrees were generated using partial least-squares methods from average fluorescence lifetimes measured at an emission wavelength of 500 nm using 460 nm excitation. A better correlation was found between the aromatic concentration of the oils and the ratio of the average fluorescence lifetimes at measured at 550 and 650 nm using 460 nm excitation. This led to a quantitative model with an accuracy of ±5.4% for aromatic concentration.

We have constructed a time-correlated single-photon counting (TCSPC) microscope system using a pulsed violet-laser diode for measuring fluorescence lifetimes below 1 ns. These compact; cool, and fast-pulsed laser diodes are much more suitable for lifetime measurements than the traditional mode-locked lasers used in the past. The laser source (LDH-400, PicoQuant GmbH) is mounted on an optical table above the microscope, and the laser beam is directed into an Olympus BX-60 microscope by means of a dichroic beamsplitter set at 45 degrees. The system operates in backscattering mode with the fluorescence emission passing back through the dichroic beamsplitter and focused into a 100 mm focal length monochromator with a PMT detector. This prototype instrument is compact (∼80 × 70 × 70 cm) and is nearly fully computer controlled by means of a SPC-730 (Becker & Hickl) PC card. We include preliminary results showing the instrument response function (IRF) of the system, and some of the factors have been adjusted to minimize the temporal width of the IRF. The instrument has been validated using a series of standard fluorophores at different emission wavelengths.

Tobacco use remains the leading cause of preventable death in the United States. Although comprehensive tobacco control has a number of essential components, support for cessation services can yield the largest short-term public health benefit. While effective treatments for tobacco dependence do exist, they are not currently available to many of the tobacco users who want and need them. Finding cost-effective, science-based strategies for reducing tobacco dependence in the United States should be a national priority.Late in 1997 a group of experts in the science of tobacco control was convened by the Center for the Advancement of Health to develop recommendations regarding the use of federal funds for treating tobacco dependence. These recommendations were prepared based on the priority of the actions and the estimated cost and effort required to implement them. Following the Master Settlement Agreement in 1998, the recommendations were adapted to address the needs of state policy makers.Effective treatments for tobacco dependence do exist; however, our nation currently lacks the capacity to deliver these services to the many millions who require them. There is a compelling need for funding from a variety of sources to create this capacity.The priority must be to develop the systems, competencies, and resources needed to deliver, and to monitor the delivery of, evidence-based treatments to tobacco users. Treatment must be delivered in an integrated manner, consistent with the needs of tobacco users. Additionally, financial barriers to treatment must be reduced, and consistent, high-quality treatment services must be ensured for all tobacco users who seek them.

The integrated photoluminescence (PL) intensities of capped InP/GaInP quantum dot structures have been measured as a function of temperature. The PL is found to decrease by up to four orders of magnitude as the temperature is raised from 18 to 300 K. The temperature data show an Arrhenius behaviour characterised by three activation energies. Analysis of this dependence indicates that the major loss mechanism is thermal activation of excitons out of the dots, followed by nonradiative recombination in the barriers. Identical samples were grown without a capping layer in order to study the morphology of the dots using an atomic force microscope (AFM).

A detailed analysis of the non-exponential behaviour of the kinetics of the initial laser level for three-micrometer generation 4 I 11/2 , in ErAG (Erbium Aluminium Garnet) crystals (laser transition 4 I 11/2 → 4 I 13/2 ), excited in the 2 H 11/2 level with short laser pulses of variable intensity, is performed. The observed non-exponentiality of the 4 I 11/2 decay and its dependence on the energy of the exciting pulse cannot be satisfactorily described with a rate equation modelling which includes only two-ion energy transfer processes among Er 3+ ions as up-conversion from the terminal laser level ( 4 I 13/2 ), up-conversion from the initial one, and cross-relaxation from 4 I 9/2 and 4 S 3/2 (thermalised, at room temperature, with 2 H 11/2 ). Our analysis has shown that the inclusion of three-ion up-conversion processes from both initial and terminal three-micrometer laser levels leads to an excellent agreement between experimental and theoretical non-exponentiality of the 4 I 11/2 decay for various pumping intensities and allows the estimation of the three-ion up-conversion rates.

The American Stop Smoking Intervention Study (ASSIST) is a programme to implement proven interventions in 17 states across the United States. ASSIST applies all that we have learned in 10 years of research on tobacco use prevention and control. The goal of this seven-year project is to reduce the prevalence of smoking and cigarette consumption in the ASSIST states. The scientific basis for ASSIST is described, followed by a general description of the project and its current status in the 17 targeted states.

A comparative luminescence study of two Ga/sub 0.52/In/sub 0.48/P-(Al/sub 0.5/Ga/sub 0.5/)/sub 0.52/In/sub 0.48/P single-quantum-well (SQW) samples with bulk and multiquantum barrier (MQB) barriers is presented. When excess carriers are only created in the quantum wells (QW's) of the samples by resonant excitation using a dye laser, the luminescence efficiency of both samples as a function of temperature is found to be essentially identical. We find, therefore, no evidence for any enhancement in the confining potential of the MQB sample over the bulk barrier sample. From Arrhenius plots of the integrated luminescence intensity, it is found that carrier loss from the QW is dominated by a nonradiative loss mechanism with an activation energy considerably smaller than that expected from direct thermal loss of electrons and holes into the barriers. We suggest that the improved device characteristics reported for lasers containing MQB's is due to effects other than the quantum interference of electrons.

An analysis of the nonexponential behavior of the kinetics of the initial laser level for three‐micron generation (4I11/2) in an Er3+(45 at. %):YAlO3 crystal under intense pump in the 4S3/2 level is performed. The observed nonexponential 4I11/2 decay can be satisfactorily described by the rate equation model which includes energy transfer processes inside the system of erbium ions, such as up‐conversion from 4I13/2 and 4I11/2 and cross‐relaxation from 4S3/2 and 4I9/2 provided only a small fraction (β21≊0.11) of the excitation from 4I11/2 level reaches the terminal laser level, 4I13/2. The low value of β21 and the observed reduction of the fluorescent lifetime of 4I11/2 with the increasing erbium doping could be related to the presence of accidental impurities.

This article summarizes the theoretical underpinnings, substantive contents, and limitations of comprehensive social-influences-based drug abuse prevention programming. This type of programming has produced the most consistently successful preventive effects. There is some evidence that one major part of these programs, changing social norms, is an essential ingredient for successful drug abuse prevention programming. Research suggests that these effects may not be contingent on the use of refusal assertion training, a prototype activity of social-influences-based prevention programs. Because programs, when disseminated to the public, often contain only a subset of lessons from the social influences curriculum, there remains the potential error of implementing a combination of lessons that may not be effective. Further, there is evidence that other types of prevention programming, such as physical consequences programming, may be successful in some situations. Finally, social-influences-based programming may not be as effective with some subpopulations such as high-risk youths.

This article first provides an overview of a sequential approach to conducting research. This model and similar sequential approaches have sometimes been referred to as the phases of research model. Next, the article offers a summary of what has been learned from this research and offers some thoughts on what is needed in future prevention research efforts, particularly in alcohol, tobacco, and other drug abuse prevention. The research agendas of three federal agencies are provided, the National Institute on Alcohol Abuse and Alcoholism (NIAAA), the National Cancer Institute (NCI), and the Center for Substance Abuse Prevention (CSAP).

Tobacco has a long history of use in the U.S., and its serious health effects have been well-documented during the past half century, U.S. efforts to control tobacco use and tobacco-related morbidity and mortality have been reasonably successful over the past 25 years, during which time there has been a 34 percent reduction in adult smoking. Nevertheless, tobacco use remains a significant public health problem in the U.S., with more than 430,000 tobacco-related deaths per year and over one-fourth of the population continuing to smoke. Many organizations are involved in tobacco use control activities, the most broadly focused of which is the National Cancer Institute (NCI). As an example of the type of program needed to address the problem of tobacco use on a national scale, the NCI's public health research plan and activities are described and its emphasis on a data-based decision matrix in its approach to tobacco and cancer control research and applications of research is discussed. Finally, future approaches to tobacco use control in the U.S. are suggested.

The increasing miniaturisation of integrated circuits has resulted in devices with lead spacings as small as 0.008″. Laser soldering has the potential to overcome many of the problems encountered with these devices by conventional soldering technologies. Nd:YAG laser soldering of a 224-lead ceramic chip onto a FR4 circuit board is described, using experimental design to optimise the laser parameters for soldering. In order to improve solder joint quality and repeatability, a rigorous thermal analysis is undertaken using a finite element model to investigate the temperature rise variations between the joints. Thermocouple measurements are made in real time of the laser soldering process to confirm the finite element model predictions.

The development of many new technologically important devices is limited by the ability of industry to produce and process materials to required standards. Further progress in many cases is limited by the present understanding of many of the properties of relevant materials. Laser-induced photoluminescence spectroscopy and Raman scattering are two optical techniques which can probe many fundamental characteristics of matter. Recent developments in the instrumentation used to acquire and analyze optical data has incresed the versatility of these probes. This article describes a state of the art optical characterisation facility and discusses the application of these spectroscopic techniques to aid an improved understanding of several important semiconducting and insulating materials.

This paper appraises the major options for the achievement of national targets for the reduction of teenage smoking in Western countries, which has changed little in recent years. The criteria for appraisal include efficacy, cost to the health sector, reach (that is, replica bility), and impact (the combination of reach and efficacy). The major inter ventions appraised include school health education, media and school pro grammes for youth, media and com munity programmes for all age groups, prevention of sales to teenagers, re strictions on smoking in schools, adver tising bans, fiscal policy, and media advocacy. Interventions aimed primarily at youth are likely to have a delaying effect only, and sophisticated school pro grammes, though potentially valuable, have proved difficult to implement effec tively on a large scale. Priority should therefore be given to broad-based inter ventions aimed at the community as a whole, including mass campaigns for all age groups, fiscal policy, restrictions on smoking, and bans on advertising. Mass campaigns may be more effective than schools at reaching high risk groups. A continuous programme of media advo cacy is essential to secure both the initial allocation and the retention of the resources required for an effective national programme. (Tobacco Control 1995; 4: 266-277)

The photoluminescence (PL) of an ${\mathrm{In}}_{0.48}$${\mathrm{Ga}}_{0.52}$P/(${\mathrm{Al}}_{0.2}$${\mathrm{Ga}}_{0.8}$${)}_{0.52}$${\mathrm{In}}_{0.48}$P multiple-quantum-well sample composed of wells of various widths has been measured as a function of temperature. The presence of LO-phonon replicas at low temperature for the largest well indicates that the PL is dominated by localized excitons. This is further confirmed by the variation of the PL peak energies and PL linewidths as the temperature is increased above 4.2 K. The temperature dependence of the integrated PL intensities shows that the major loss mechanism is thermal activation of electron-hole pairs out of the wells followed by nonradiative recombination in the barriers. The experimental data substantiate the proposition that the poor thermal characteristics of visible lasers is caused by carrier leakage out of relatively shallow wells.