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\"Death, light, figuration and, especially, analogical expressions of figuration, are the primary subjects of this book. They generate associated interests: the relation of literature and science, the methodology of thought and argument, and the processes of narrative, discovery, and interpretation. Creativity, optics, rhetoric, and language are focal as well\"-- Provided by publisher.

Estimating the burden of disease attributable to long-term exposure to fine particulate matter (PM2.5) in ambient air requires knowledge of both the shape and magnitude of the relative risk (RR) function. However, adequate direct evidence to identify the shape of the mortality RR functions at the high ambient concentrations observed in many places in the world is lacking. We developed RR functions over the entire global exposure range for causes of mortality in adults: ischemic heart disease (IHD), cerebrovascular disease (stroke), chronic obstructive pulmonary disease (COPD), and lung cancer (LC). We also developed RR functions for the incidence of acute lower respiratory infection (ALRI) that can be used to estimate mortality and lost-years of healthy life in children < 5 years of age. We fit an integrated exposure-response (IER) model by integrating available RR information from studies of ambient air pollution (AAP), second hand tobacco smoke, household solid cooking fuel, and active smoking (AS). AS exposures were converted to estimated annual PM2.5 exposure equivalents using inhaled doses of particle mass. We derived population attributable fractions (PAFs) for every country based on estimated worldwide ambient PM2.5 concentrations. The IER model was a superior predictor of RR compared with seven other forms previously used in burden assessments. The percent PAF attributable to AAP exposure varied among countries from 2 to 41 for IHD, 1 to 43 for stroke, < 1 to 21 for COPD, < 1 to 25 for LC, and < 1 to 38 for ALRI. We developed a fine particulate mass-based RR model that covered the global range of exposure by integrating RR information from different combustion types that generate emissions of particulate matter. The model can be updated as new RR information becomes available.

Current air quality standards for particulate matter (PM) use the PM mass concentration [PM with aerodynamic diameters ≤ 10 μm (PM(10)) or ≤ 2.5 μm (PM(2.5))] as a metric. It has been suggested that particles from combustion sources are more relevant to human health than are particles from other sources, but the impact of policies directed at reducing PM from combustion processes is usually relatively small when effects are estimated for a reduction in the total mass concentration. We evaluated the value of black carbon particles (BCP) as an additional indicator in air quality management. We performed a systematic review and meta-analysis of health effects of BCP compared with PM mass based on data from time-series studies and cohort studies that measured both exposures. We compared the potential health benefits of a hypothetical traffic abatement measure, using near-roadway concentration increments of BCP and PM(2.5) based on data from prior studies. Estimated health effects of a 1-μg/m3 increase in exposure were greater for BCP than for PM(10) or PM(2.5), but estimated effects of an interquartile range increase were similar. Two-pollutant models in time-series studies suggested that the effect of BCP was more robust than the effect of PM mass. The estimated increase in life expectancy associated with a hypothetical traffic abatement measure was four to nine times higher when expressed in BCP compared with an equivalent change in PM(2.5) mass. BCP is a valuable additional air quality indicator to evaluate the health risks of air quality dominated by primary combustion particles.

Background: Evidence based largely on US cohorts suggests that long-term exposure to fine particulate matter is associated with cardiovascular mortality. There is less evidence for other pollutants and for cardiovascular morbidity. By using a cohort of 836,557 patients age 40 to 89 years registered with 205 English general practices in 2003, we investigated relationships between ambient outdoor air pollution and incident myocardial infarction, stroke, arrhythmia, and heart failure over a 5-year period. Methods: Events were identified from primary care records, hospital admissions, and death certificates. Annual average concentrations in 2002 for particulate matter with a median aerodynamic diameter <10 (PM₁₀) and <2.5 microns, nitrogen dioxide (NO₂), ozone, and sulfur dioxide at a 1 × 1 km resolution were derived from emission-based models and linked to residential postcode. Analyses were performed using Cox proportional hazards models adjusting for relevant confounders, including social and economic deprivation and smoking. Results: While evidence was weak for relationships with myocardial infarction, stroke, or arrhythmia, we found consistent associations between pollutant concentrations and incident cases of heart failure. An interquartile range change in PM₁₀ and in NO₂ (3.0 and 10.7 μm³, respectively) both produced a hazard ratio of 1.06 (95% confidence interval = 1.01-1.11) after adjustment for confounders. There was some evidence that these effects were greater in more affluent areas. Conclusions: This study of an English national cohort found evidence linking long-term exposure to particulate matter and NO₂ with the development of heart failure. We did not, however, replicate associations for other cardiovascular outcomes that have been reported elsewhere.

Scotland has had a uniquely important military history over the last five centuries. Conflict with England in the 16th century, Jacobite rebellions in the 18th century, 20th-century defences and the two world wars, as well as the Cold War, all resulted in significant cartographic activity. In this book, two map experts explore the extraordinary rich legacy of Scottish military mapping, showing and explaining the variety of military maps produced for different purposes, including fortification plans, reconnaissance mapping, battle plans, military roads and route-way plans,tactical maps, plans of mines, enemy maps showing targets, as well as plans showing the construction of defences. In addition to plans, elevations, and views, they also discuss unrealised proposals and projected schemes.

Frequency combs produced by solitons in silicon-based optical microresonators are used to transmit data streams of more than 50 terabits per second in telecommunication wavelength bands. Scaling up telecommunications Frequency combs—light sources that emit a wide spectrum of sharp lines with equally spaced frequencies—have recently become of interest for use in high-capacity optical data transmission. The possibility of producing frequency combs using compact, chip-integrated microresonators promises scalability and practical applicability. Christian Koos et al . make use of a recently developed technique whereby frequency combs are produced by continuously circulating optical solitons—waveforms that preserve their shape during propagation—in silicon-based microresonators. They use two interleaved, chip-based frequency combs to demonstrate transmission of a data stream of more than 50 terabits per second on 179 individual optical carriers in telecommunication wavelength bands. The technology could be used to develop efficient, highly scalable communication systems that could help to address the challenge of a continually growing demand for data capacity. Solitons are waveforms that preserve their shape while propagating, as a result of a balance of dispersion and nonlinearity 1 , 2 . Soliton-based data transmission schemes were investigated in the 1980s and showed promise as a way of overcoming the limitations imposed by dispersion of optical fibres. However, these approaches were later abandoned in favour of wavelength-division multiplexing schemes, which are easier to implement and offer improved scalability to higher data rates. Here we show that solitons could make a comeback in optical communications, not as a competitor but as a key element of massively parallel wavelength-division multiplexing. Instead of encoding data on the soliton pulse train itself, we use continuous-wave tones of the associated frequency comb as carriers for communication. Dissipative Kerr solitons (DKSs) 3 , 4 (solitons that rely on a double balance of parametric gain and cavity loss, as well as dispersion and nonlinearity) are generated as continuously circulating pulses in an integrated silicon nitride microresonator 5 via four-photon interactions mediated by the Kerr nonlinearity, leading to low-noise, spectrally smooth, broadband optical frequency combs 6 . We use two interleaved DKS frequency combs to transmit a data stream of more than 50 terabits per second on 179 individual optical carriers that span the entire telecommunication C and L bands (centred around infrared telecommunication wavelengths of 1.55 micrometres). We also demonstrate coherent detection of a wavelength-division multiplexing data stream by using a pair of DKS frequency combs—one as a multi-wavelength light source at the transmitter and the other as the corresponding local oscillator at the receiver. This approach exploits the scalability of microresonator-based DKS frequency comb sources for massively parallel optical communications at both the transmitter and the receiver. Our results demonstrate the potential of these sources to replace the arrays of continuous-wave lasers that are currently used in high-speed communications. In combination with advanced spatial multiplexing schemes 7 , 8 and highly integrated silicon photonic circuits 9 , DKS frequency combs could bring chip-scale petabit-per-second transceivers into reach.

Solitons are shape preserving waveforms that are ubiquitous across nonlinear dynamical systems from BEC to hydrodynamics, and fall into two separate classes: bright solitons existing in anomalous group velocity dispersion, and switching waves forming ‘dark solitons’ in normal dispersion. Bright solitons in particular have been relevant to chip-scale microresonator frequency combs, used in applications across communications, metrology, and spectroscopy. Both have been studied, yet the existence of a structure between this dichotomy has only been theoretically predicted. We report the observation of dissipative structures embodying a hybrid between switching waves and dissipative solitons, existing in the regime of vanishing group velocity dispersion where third-order dispersion is dominant, hence termed as ‘zero-dispersion solitons’. They are observed to arise from the interlocking of two modulated switching waves, forming a stable solitary structure consisting of a quantized number of peaks. The switching waves form directly via synchronous pulse-driving of a Si 3 N 4 microresonator. The resulting comb spectrum spans 136 THz or 97% of an octave, further enhanced by higher-order dispersive wave formation. This dissipative structure expands the domain of Kerr cavity physics to the regime near to zero-dispersion and could present a superior alternative to conventional solitons for broadband comb generation. Here, the authors find the missing link for soliton microcombs that exist at the boundary where the group velocity dispersion of light changes sign: zero-dispersion solitons. The resulting microresonator frequency comb, based in Si3N4, spans almost an octave.