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We develop rapid chemical vapor sensors and micro gas chromatography (μGC) analyzers based on the optofluidic ring resonator (OFRR). An OFRR is a micro-sized thin-walled glass capillary; the circular cross-section of the capillary acts as an optical ring resonator while the whispering gallery modes or circulating waveguide modes (WGMs) supported by the ring resonator interact with the vapor samples passing through the capillary. The OFRR interior surface is coated with a vapor-sensitive polymer. The analyte and polymer interaction causes the polymer refractive index (RI) and the thickness to change, which is detected as a WGM spectral shift. Owing to the excellent fluidics, the OFRR vapor sensor exhibits sub-second detection and recovery time with a flow rate of 1 mL/min. On-column separation and detection in the OFRR based μGC system is also demonstrated, showing efficient separation of vapor mixtures and presenting highly reproducible retention time for the individual analyte. Compared to the conventional GC system, the OFRR μGC has the advantage of small size, rapid response, and high selectivity over a short length of column.
Tropical forest regions in equatorial Africa are threatened with degradation, deforestation and biodiversity loss as a result of land-cover change. We investigated historical land-cover dynamics in unprotected forested areas of the Littoral Region in south-western Cameroon during 1975–2017, to detect changes that may influence this important biodiversity and wildlife area. Processed Landsat imagery was used to map and monitor changes in land use and land cover. From 1975 to 2017 the area of high-value forest landscapes decreased by c. 420,000 ha, and increasing forest fragmentation caused a decline of c. 12% in the largest patch index. Conversely, disturbed vegetation, cleared areas and urban areas all expanded in extent, by 32% (c. 400,000 ha), 5.6% (c. 26,800 ha) and 6.6% (c. 78,631 ha), respectively. The greatest increase was in the area converted to oil palm plantations (c. 26,893 ha), followed by logging and land clearing (c. 34,838 ha), all of which were the major factors driving deforestation in the study area. Our findings highlight the increasing threats facing the wider Littoral Region, which includes Mount Nlonako and Ebo Forest, both of which are critical areas for regional conservation and the latter a proposed National Park and the only sizable area of intact forest in the region. Intact forest in the Littoral Region, and in particular at Ebo, merits urgent protection.
High Na intake and chronically elevated cortisol levels are independently associated with the development of chronic diseases. In adults, high Na intake is associated with high levels of urinary cortisol. We aimed to determine the association between urinary Na and K and urinary cortisol in a cross-sectional sample of Australian schoolchildren and their mothers. Participants were a sample of Australian children (n 120) and their mothers (n 100) recruited through primary schools. We assessed Na, K, free cortisol and cortisol metabolites in one 24 h urine collection. Associations between 24 h urinary electrolytes and 24 h urinary cortisol were assessed using multilevel mixed-effects linear regression models. In children, urinary Na was positively associated with urinary free cortisol (β=0·31, 95 % CI 0·19, 0·44) and urinary cortisol metabolites (β=0·006, 95 % CI 0·002, 0·010). Positive associations were also observed between urinary K and urinary free cortisol (β=0·65, 95 % CI 0·23, 1·07) and urinary cortisol metabolites (β=0·02, 95 % CI 0·03, 0·031). In mothers, urinary Na was positively associated with urinary free cortisol (β=0·23, 95 % CI 0·01, 0·50) and urinary cortisol metabolites (β=0·008, 95 % CI 0·0007, 0·016). Our findings show that daily Na and K intake were positively associated with cortisol production in children and their mothers. Investigation of the mechanisms involved and the potential impact of Na reduction on cortisol levels in these populations is warranted.
Individuals with primary brain tumors experience a range of physical, cognitive and psychosocial sequelae which impact their independence, safety and quality of life. These impairments may be addressed through rehabilitation intervention. Despite acknowledgement that timely rehabilitation services over the course of the disease process is of benefit, few outpatient neuro-oncology treatment teams include a rehabilitation professional. Purpose: The aims are: (1) to describe a rehabilitation consultation model of care integrated into outpatient neuro-oncology treatment for individuals with primary brain tumors; and (2) to describe the characteristics of individuals referred for rehabilitation services. Methods: This retrospective descriptive study examined data from 200 individuals that received rehabilitation consultation from January 2015 to March 2016 at Princess Margaret Hospital, Pencer Brain Tumor Centre. Information on patient demographics, referral characteristics, and number of patient care visits was collected. Descriptive statistics were calculated. Preliminary Results: Of all patients, (n=195), the most common diagnosis is glioblastoma, 39% (n=76), and 50% are 50-69 years of age (M=55, SD=15.0). The most common reason for initial referral was decline in physical functioning, strength and balance (41%). In 77% of cases, patients were seen immediately at the time of referral. In total, 540 consultations were completed (face-to-face=230, telephone=310) with 2.78 on average (SD=4.0) per patient. Conclusion: Given the range of symptoms that individuals with primary brain tumors experience coupled with changes in functional status as the disease progresses, integrated and timely rehabilitation consultation is feasible.
There are two schools of thought concerning the most appropriate environment in which to select breeding animals. One says ‘ Always select animals under environmental conditions similar to those where they are to be used ‘. The other says ‘ Select breeding animals in the optimum environment so that they have the best chance of revealing their genetic capabilities ‘. Experiments on growth of laboratory mice and experience with European cattle in the tropics have shown the advisability of the first course in these cases. In regard to hill sheep and dairy cattle in Britain, on the other hand, practice favours the second course, but there is little experimental evidence to support it.
During the last decade or more we have heard a great deal about progeny testing. Discussion has centred round three chief points. Under what conditions can selection by progeny testing lead to an increase in the rate of genetic improvement ? What method of testing and interpretation of results is most efficient and most practical ? How should the results be applied—that is in what way should the tested animals be used ?
In their paper reprinted herein (page 79) Johansson and Robertson have shown to what extent modern genetical theory can answer the second of these questions. It now remains for the executive agencies of livestock improvement to demonstrate the practical utility of the schemes they outline. We must wait some time, especially for slow-breeding animals like cattle, before the results of such a demonstration are available.
We report photometric results from 44 runs at 11 observatories during the international campaign ‘TT Ari–94’. No coherent oscillations in the frequency range 10… 900 cycle d−1 are found. The highest peaks in the power spectrum cover the wide range of 28… 139 cycle d−1. Variations occur at a few preferred time-scales rather than at one cycle length, with a possible secular decrease. In the frequency range 90… 900 cycle d−1 the power spectrum obeys a power law with slope γ ranging from 0.8 to 2.6 for different runs.
TT Ari is one of the brightest cataclysmic variables and remains one of the most interesting objects of this class. It exhibits a variety of phenomena observed at time-scales from seconds to months. A recent detailed photometric study of this object and a bibliographical overview may be found in Tremko et al. (1996). Tremko et al. (1992, 1993, 1994) discuss aspects of the TT Ari–88 campaign. Our campaign TT Ari–94 was unprecedented, as the observations were longitude-dispersed, from Japan through Turkmenia, to Europe and the American continent. Moreover, our optical data on October 7 partially overlap with the HST observations obtained by Home & Welsh (1995, private communication). The numerical results of observations obtained during these nights are shown in Table 1.
The Washington Multiplicity Catalog (WMC) project is an effort to address the often conflicting nomenclature schemes used by astronomers in different fields of double and multiple star research, by compiling a catalog of all known binary and multiple systems, then assigning a consistent (insofar as possible) component designation to each component. Components are treated in the same manner whether stellar or sub-stellar (e.g., brown dwarf, exosolar planet) in nature. This effort was begun shortly before the 2000 IAU General Assembly in Manchester, UK. A sample version of the planned catalog was presented at IAU Colloquium 191, held in Mérida, México in February 2003, and a modified version of this sample will be presented at the July 2003 GA in Sydney, Australia. Finally, if the nomenclature and catalog format are agreed upon, a full-sky version of the catalog will be created in time for the 2006 GA in Prague.
The new observing and reduction techniques available to astronomers have led to remarkable changes in the field of double and multiple stars. New classes of companions, such as brown dwarfs and exoplanets, have been discovered. Binaries which previously constituted distinct classes are now observable by multiple techniques. With many long-baseline optical interferometers operational or planned, with improvements in other techniques, and with astrometric space-based missions in various states of planning and funding, the situation is likely to become more complicated. The result is greater understanding for the scientist, but greater challenges for the cataloger!
The “problem” is that purveyors of different techniques use different nomenclature, both in terms of root designation and component identifier. It is this latter inconsistency which causes the most confusion and is the topic of this Special Session.
This talk will illustrate some of the many designation ambiguities and summarize efforts made during the past few years to address this problem.
Binaries could provide the best niches for life in the Galaxy. Although counterintuitive, this assertion follows directly from stellar tidal interaction theory and the evolution of lower mass stars. There is strong evidence that chromospheric activity of rapidly rotating young stars may be high enough to cause mass loss from atmospheres of potentially habitable planets. The removal of atmospheric water is most critical. Tidal breaking in binaries could help reduce magnetic dynamo action and thereby chromospheric activity in favour of life. We call this the Binary Habitability Mechanism (BHM) that we suggest allows for water retention at levels comparable to or better than the Earth. We discuss novel advantages that life may exploit, in these cases, and suggest that life may even thrive on some circumbinary planets. We find that while many binaries do not benefit from BHM, high-quality niches do exist for various combinations of stars between 0.55 and 1.0 solar masses. For a given pair of stellar masses, BHM operates only for certain combinations of period and eccentricity. Binaries having a solar-type primary seem to be quite well-suited niches having wide and distant habitable zones with plentiful water and sufficient light for photosynthetic life. We speculate that, as a direct result of BHM, conditions may be suitable for life on several planets and possibly even moons of giant planets orbiting some binaries. Lower mass combinations, while more restrictive in parameter space, provide niches lasting many billions of years and are rich suppliers of photosynthetic photons. We provide a publicly available web-site (http://bit.ly/BHM-calculator or http://bit.ly/BHM-calculator-mirror), which calculates the BHM effects presented in this paper.
1.1.1. In October 1980 the Council of the Faculty of Actuaries set up a Working Party with the following brief:—
(1) To investigate the criteria by which the solvency of life assurance companies should be assessed and to determine the amount of the solvency margin which should be required in practice by supervisory authorities. The existing requirements of the E.E.C. Life Establishment Directive should be considered with a view to recommending any desirable alterations thereto to be made when those requirements are reviewed in due course by the E.E.C. Commission. In carrying out its work the Working Party should co-operate with Working Parties or Committees of other actuarial bodies.
(2) To report the result of their investigations to Council.
We investigate the interaction between a developed country that imports a carbon-intensive product, such as electricity, and a transitioning economy that exports the product. Production of the good generates a transboundary externality related to climate change; if this externality is priced improperly, the application of a feed-in tariff or border tax adjustment can provide an indirect policy instrument. We analyze the application of such a measure in a stark model where the importing country cares about climate-related damages while the exporting country does not; this can be viewed as reflecting a scenario where the (developed) importing country is more concerned about climate change than is the (transitioning) exporting economy. Because climate change will occur over a long time frame, the problem is dynamic. In this modeling context, we describe the manner in which the (second-best) tariff-cum-border tax adjustment relates to the carbon stock.
This chapter addresses changes in weather and climate events relevant to extreme impacts and disasters. An extreme (weather or climate) event is generally defined as the occurrence of a value of a weather or climate variable above (or below) a threshold value near the upper (or lower) ends (‘tails’) of the range of observed values of the variable. Some climate extremes (e.g., droughts, floods) may be the result of an accumulation of weather or climate events that are, individually, not extreme themselves (though their accumulation is extreme). As well, weather or climate events, even if not extreme in a statistical sense, can still lead to extreme conditions or impacts, either by crossing a critical threshold in a social, ecological, or physical system, or by occurring simultaneously with other events. A weather system such as a tropical cyclone can have an extreme impact, depending on where and when it approaches landfall, even if the specific cyclone is not extreme relative to other tropical cyclones. Conversely, not all extremes necessarily lead to serious impacts. [3.1]
Many weather and climate extremes are the result of natural climate variability (including phenomena such as El Niño), and natural decadal or multi-decadal variations in the climate provide the backdrop for anthropogenic climate changes. Even if there were no anthropogenic changes in climate, a wide variety of natural weather and climate extremes would still occur. [3.1]
A changing climate leads to changes in the frequency, intensity, spatial extent, duration, and timing of weather and climate extremes, and can result in unprecedented extremes. Changes in extremes can also be directly related to changes in mean climate, because mean future conditions in some variables are projected to lie within the tails of present-day conditions. Nevertheless, changes in extremes of a climate or weather variable are not always related in a simple way to changes in the mean of the same variable, and in some cases can be of opposite sign to a change in the mean of the variable. Changes in phenomena such as the El Nino-Southern Oscillation or monsoons could affect the frequency and intensity of extremes in several regions simultaneously. [3.1]
With the financial services industries in the member countries of the European Union coming under increasing attention resulting in relaxation of cross border controls, this paper addresses some pensions matters in this European context and how they may relate to the U.K. The main theme of the paper is the book reserve approach to pensions provision. Details of the German book reserve method are provided before developing possible ways in which this philosophy could be introduced into the U.K. These possibilities are assessed and consideration given to the effect they may have on the economy, commerce, the pension fund industry and, not least, the actuarial profession in the U.K.
The Clyde Sea Area has long been associated with shellfish fishing and has shared in the large expansion which has occurred during the past thirty-five years in the Scottish industry. Here, as elsewhere, the expansion has been helped by the establishment of processing facilities and in 1983 the landings of shellfish from the Clyde reached £4–5 million in value.
The sea bed and shores in the Clyde provide a wide range of habitats which is reflected in the commercially important species which are taken. They range from the fine mud in which Norway lobsters burrow, through sand in which cockles occur, and sandy gravel which is suitable for scallops and queens, to the hard ground inhabited by lobsters and the rocky shores on which periwinkles abound.
The most important shellfish in the Clyde, with annual landings valued at £3–75 million, is the Norway lobster, which is dealt with by Bailey et al. (1986). This contribution considers all the other species. The most valuable are scallops and queens, which now together exceed £400,000 p.a. in value. Periwinkles are gathered extensively on rocky shores. Squid are taken sporadically, by light trawlers and seine-netters, and occasionally, when they are especially abundant, form the basis of a directed fishery. Creel fishing for lobsters, edible crabs and velvet swimming crabs is less widespread than elsewhere round Scotland, but provides a useful income for a few boats. Mussels and cockles are gathered on a small scale, and cockle stocks in the Clyde proved especially valuable after English and Welsh stocks had been depleted by the severe winter of 1962–63. The only surviving fishery for the native oyster in Scotland is in the Clyde, in Loch Ryan, and attempts are being made to improve its production. Sea lochs in the Clyde offer conditions, particularly shelter, suitable for cultivating filterfeeding bivalve molluscs.
Hypovitaminosis D may be associated with diabetes, hypertension and CHD. However, because studies examining the associations of all three chronic conditions with circulating 25-hydroxyvitamin D (25(OH)D) and 1,25-dihydroxyvitamin D (1,25(OH)2D) are limited, we examined these associations in the US Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial (n 2465). Caucasian PLCO participants selected as controls in previous nested case–control studies of 25(OH)D and 1,25(OH)2D were included in this analysis. Diabetes, CHD and hypertension prevalence, risk factors for these conditions and intake of vitamin D and Ca were collected from a baseline questionnaire. Results indicated that serum levels of 25(OH)D were low ( < 50 nmol/l) in 29 % and very low ( < 37 nmol/l) in 11 % of subjects. The prevalence of diabetes, hypertension and CHD was 7, 30 and 10 %, respectively. After adjustment for confounding by sex, geographical location, educational level, smoking history, BMI, physical activity, total dietary energy and vitamin D and Ca intake, only diabetes was significantly associated with lower 25(OH)D and 1,25(OH)2D levels. Caucasians who had 25(OH)D ≥ 80 nmol/l were half as likely to have diabetes (OR 0·5 (95 % CI 0·3, 0·9)) compared with those who had 25(OH)D < 37 nmol/l. Those in the highest quartile of 1,25(OH)2D ( ≥ 103 pmol/l) were less than half as likely to have diabetes (OR 0·3 (95 % CI 0·1, 0·7)) than those in the lowest quartile ( < 72 pmol/l). In conclusion, the independent associations of 25(OH)D and 1,25(OH)2D with diabetes prevalence in a large population are new findings, and thus warrant confirmation in larger, prospective studies.
An oxide-dispersion strengthened (ODS) Ni3Al-based alloy has been fabricated and creep tested. Previously reported data for minimum creep rate as a function of stress indicated that two creep mechanisms operate at intermediate temperatures of 732 and 816°C . This paper reports the results of recent interrupted creep tests and fractographic studies which serve to identify the two creep mechanisms. Creep at low stresses or low creep-rates occurs by constrained growth of cavities on transverse grain boundaries. In this low stress region an apparent stress exponent of 5.1 is observed. Creep at high stresses or high creep-rates results from the bulk deformation of grains by power law creep with a much smaller contribution due to grain boundary cavitation. The stress exponents of 13 and 22 observed in this high stress region are typical of ODS alloys. In both regions fracture is observed to be mixed mode with a large transgranular component due to the high grain aspect ratio developed in this material. Limited data at 982°C indicate the occurrence of only one mechanism which can be described by a stress exponent of 9.1. It was not possible, based on fractographic studies, to associate the creep mechanism at 982°C with either of those observed at the intermediate temperatures. No fractographic studies were performed at 649°C due to lack of valid specimens; however, the stress exponent of 13.5 observed at 649°C suggests that creep occurs by deformation of the grains.
We report on the use of lithium ion (Li+) drifting1 as a sensitive means to study Si self-interstitial (SiI) diffusion.2 Li+ properties in silicon are well known from extensive ion drift studies and Li+ interactions with dopants and point defects.3 We have used this low temperature (∼100°C) technique in combination with Si1 injection from oxides to delineate, identify and eliminate D defects4 in certain p-type floating zone (FZ) Si single crystals.5 Our results suggest Si1 diffusion occurs to a depth of at least 10 mm into the bulk during phosphorus (P) diffusion with oxidation (i.e., POCI3 process) at 950°C for 100 min. Process modeling of this lower bound SiI diffusion using SUPREM-IV9 results in a Sii diffusivity of 3.5×10−6 cm2/s at 950°C.
Up to 8 per cent of SO3 may be incorporated into the crystalline lattice of C2S if burned in the presence of CaSO4. C3S may be formed only in the presence of F-. Under these conditions up to 5 per cent of SO3 may be incorporated. In the presence of CaSO4 and CaF2 in the raw meal portland clinkers may be formed that contain simultaneously the phases C3S and C4A3S. Clinkers of this kind yield cements with favorable strength properties at “optimum gypsum” additions.