Model Checking Games for the Quantitative mu-Calculus

We investigate quantitative extensions of modal logic and the modal mu-calculus, and study the question whether the tight connection between logic and games can be lifted from the qualitative logics to their quantitative counterparts. It turns out that, if the quantitative mu-calculus is defined in an appropriate way respecting the duality properties between the logical operators, then its model checking problem can indeed be characterised by a quantitative variant of parity games. However, these quantitative games have quite different properties than their classical counterparts, in particular they are, in general, not positionally determined. The correspondence between the logic and the games goes both ways: the value of a formula on a quantitative transition system coincides with the value of the associated quantitative game, and conversely, the values of quantitative parity games are definable in the quantitative mu-calculus

The tyranny of regional unemployment rates

Although there is a substantial body of literature on labour market analysis, most of it ignores the spatial dimension of the labour market. A spatial perspective in analysing labour market processes is important for several reasons. FIRST, labour markets are by no means as homogeneous as conventional labour market theories assume. SECOND, most countries are displaying strong regional variations in the dynamics of unemployment. THIRD, geographical space exerts a frictional effect on labour market processes. Regional unemployment rates appear to be the most important indicators for analysing labour market processes from a spatial perspective. The paper aims to discuss some of the problems that are associated with the use of regional unemployment rates. We will focus attention on conceptual problems, problems of data quality and on some of the new problems that have arisen due to the widespread use of new computer technology. Solutions to many of the problems are obvious, but many of the new problems will require some extra effort for their solution. The tyranny that threatens the research community is that regional unemployment data exercise a power over us that can lead the naive to misinterpretations. The data may mislead even the most righteous among us. A good deal of research effort is often given to overcome the tyranny that is found in the columns and rows that the lay public likes to call statistics. The discussion will be enriched by means of a study utilizing regional unemployment rates at the district level in West Germany.

Lunar Resources Using Moderate Spectral Resolution Visible and Near-infrared Spectroscopy: Al/si and Soil Maturity

Modern visible and near-infrared detectors are critically important for the accurate identification and relative abundance measurement of lunar minerals; however, even a very small number of well-placed visible and near-infrared bandpass channels provide a significant amount of general information about crucial lunar resources. The Galileo Solid State Imaging system (SSI) multispectral data are an important example of this. Al/Si and soil maturity will be discussed as examples of significant general lunar resource information that can be gleaned from moderate spectral resolution visible and near-infrared data with relative ease. Because quantitative-albedo data are necessary for these kinds of analyses, data such as those obtained by Galileo SSI are critical. SSI obtained synoptic digital multispectral image data for both the nearside and farside of the Moon during the first Galileo Earth-Moon encounter in December 1990. The data consist of images through seven filters with bandpasses ranging from 0.40 microns in the ultraviolet to 0.99 microns in the near-infrared. Although these data are of moderate spectral resolution, they still provide information for the following lunar resources: (1) titanium content of mature mare soils based upon the 0.40/0.56-micron (UV/VIS) ratio; (2) mafic mineral abundance based upon the 0.76/0.99-micron ratio; and (3) the maturity or exposure age of the soils based upon the 0.56-0.76-micron continuum and the 0.76/0.99-micron ratio. Within constraints, these moderate spectral resolution visible and near-infrared reflectance data can also provide elemental information such as Al/Si for mature highland soils

The perplexing continuum slope of Mars: Effects of thin ferric coatings and viewing geometry

The experiment discussed here was designed to constrain interpretations of variations in continuum slope variations which define several spectral annuli on the flanks of Olympus Mons, observed in the Imaging Spectrometer (IMS) data. The IMS Olympus Mons data reveal that the rings, seen as alternating brighter and darker reflectance in Viking data, correspond to annuli of alternating shallower and steeper continuum slope. At least three factors contributing to continuum slope are identified: ferric coating thickness, viewing geometry, and surface texture. Because the Olympus Mons spectral annuli were observed at nearly constant backscatter geometries in the ISM data, with only slight viewing variations due to the volcanoe's flank slopes, the difference of continuum slope between annuli probably cannot be explained by viewing geometry alone. This suggests that the variation of some fundamental surface characteristics, such as ferric dust/rind thickness or surface texture, is the cause of the Olympus Mons special annuli observed in the ISM imaging spectrometer data

Quantifying uncertainties in projections of extremes—a perturbed land surface parameter experiment

Uncertainties in the climate response to a doubling of atmospheric CO2 concentrations are quantified in a perturbed land surface parameter experiment. The ensemble of 108 members is constructed by systematically perturbing five poorly constrained land surface parameters of global climate model individually and in all possible combinations. The land surface parameters induce small uncertainties at global scale, substantial uncertainties at regional and seasonal scale and very large uncertainties in the tails of the distribution, the climate extremes. Climate sensitivity varies across the ensemble mainly due to the perturbation of the snow albedo parameterization, which controls the snow albedo feedback strength. The uncertainty range in the global response is small relative to perturbed physics experiments focusing on atmospheric parameters. However, land surface parameters are revealed to control the response not only of the mean but also of the variability of temperature. Major uncertainties are identified in the response of climate extremes to a doubling of CO2. During winter the response both of temperature mean and daily variability relates to fractional snow cover. Cold extremes over high latitudes warm disproportionately in ensemble members with strong snow albedo feedback and large snow cover reduction. Reduced snow cover leads to more winter warming and stronger variability decrease. As a result uncertainties in mean and variability response line up, with some members showing weak and others very strong warming of the cold tail of the distribution, depending on the snow albedo parametrization. The uncertainty across the ensemble regionally exceeds the CMIP3 multi-model range. Regarding summer hot extremes, the uncertainties are larger than for mean summer warming but smaller than in multi-model experiments. The summer precipitation response to a doubling of CO2 is not robust over many regions. Land surface parameter perturbations and natural variability alter the sign of the response even over subtropical region

Single bubble deformation and breakup in simple shear flow

Experiments in a parallel band apparatus and a transparent concentric cylinder device allow the observation of bubble deformation (shape and orientation) and breakup as a function of the viscosity ratio λ and the Capillary number Ca. For viscosity ratios between 3.1×10−7 and 6.7×10−8, critical Capillary numbers Ca c for bubble breakup between 29 and 45 are found. It is furthermore shown that in the given parameter space no clear distinction between tip breakup and fracture can be made for bubble

Rheology of concentrated suspensions containing mixtures of spheres and fibres

Optimising flow properties of concentrated suspensions is an important issue common for many industries. The rheology of concentrated suspensions has therefore been studied intensively both experimentally and theoretically. Most studies have focused on monodisperse and polydisperse suspensions of either spheres or fibres. In practice, most suspensions contain particles that are polydisperse both in size and shape. A mixing rule for such systems is expected to be a powerful tool for engineers and product designers. Therefore in this work, suspensions of spheres, fibres and mixtures thereof were characterised using rotational shear rheometry and in-line image analyses. Thereby, total solids volume concentration and fibre fraction was varied. Results from transient and steady-state shear rheometry are discussed with respect to concentration, fibre fraction, and shear induced microstructure. Experimentally obtained viscosity data were accurately fitted using the model proposed by Farris (T Soc Rheol 12:281, 1968) for mixtures of monodisperse non-interacting spheres of different size

HYACINTH MACAWS (ANODORHYNCHUS HYACINTHINUS, PSITTACIDAE) FEEDING ON TERMITES

Abstract ∙ Hyacinth Macaws (Anodorhynchus hyacinthinus) feed largely on palm seeds and fruits. Here, we report a pair of Hyacinth Macaws feeding on termites. We visited the nesting tree of a pair of Hyacinth Macaws at the southern border of the Brazilian Pantanal on a monthly basis during one year. Macaws were present during four of these visits, and we recorded them foraging on arboreal termites in their nesting tree during one of the visits. Using their beaks, both macaw individuals repeatedly broke away bark pieces from decaying branches, and handled them with beak and feet to ingest termites found on the inner side of the bark. Nesting in decaying trees likely increases opportunities for Hyacinth Macaws to find termites, and the feeding behavior of these macaws indicates that they are familiar with and able to consume termites. This is the first report of termite consumption by this species.Resumo ∙ Arara‐azul‐grande (Anodorhynchus hyacinthinus, Psittacidae) comendo cupins Indivíduos de Arara‐azul‐grande (Anodorhynchus hyacinthinus) consomem principalmente sementes de palmeiras e frutos. Reportamos aqui um casal de Araras‐azuis‐grandes consumindo cupins. Visitamos uma árvore de nidificação na borda sul do Pantanal brasileiro mensalmente durante um ano. As araras estavam presentes em quatro visitas, e registramos consumo de cupins presentes na árvore de nidificação em uma visita. As araras repetidamente retiravam com o bico pedaços de casca de ramos podres, e manuseavam os pedaços com o bico e os pés para ingerir cupins presentes na parte interna da casca. Nidificar em árvores senescentes provavelmente aumenta a oportunidade dessas araras encontrarem cupins, e o comportamento alimentar delas indica familiaridade e habilidade em consumilos. Esse é o primeiro registro de consumo de cupins por esta espécie.

Characterization of Pregnancy Induced Changes in Glucose Metabolism

Many reports indicate that pregnancy is a diabetogenic state in which there is both insulin resistance and an exaggerated maternal glucose and insulin response to food ingestion. However, the magnitude of these aberrations and their temporal relationship have not been adequately characterized. This study utilizes the hyperglycemic clamp technique to investigate the insulin secretory response and tissue sensitivity to insulin under hyperglycemic conditions in normal and gestational diabetic pregnancies. Our results indicate that third trimester normal pregnancy is characterized by an increased first phase (108.81+/-13.03 uU/ml) and second phase (228.57+/-43.40 microunits/ml) insulin secretory response as compared to non-pregnant controls (72.93+/-15.76, 103.02+8/-12.43 ) (p\u3c0.05). However, C-peptide values did not mirror those of insulin in that normal pregnant women during the third trimester of pregnancy demonstrated a significantly lower C-peptide to insulin ratio than either non-pregnant controls or gestational diabetic women in their third trimester (p\u3c0.05). In contrast to normal pregnant women, gestational diabetic women in their third trimester of pregnancy showed no increase in insulin secretion. Glucose uptake under hyperglycemic conditions tended to decrease progressively through pregnancy and was significantly lower than non-pregnant controls (10. 60+/-1. 19 mg/kg/min) in the third trimester of normal pregnancy (7.20+/-0.79 mg/kg/min) and gestational diabetic pregnancy (5.87+/-0.27 mg/kg/min) (p\u3c0.05). Furthermore, there was a significantly lower tissue sensitivity to insulin (defined by the ratio of the glucose uptake to the circulating insulin level during the final sixty minutes of the study) in normal third trimester pregnancies (0.03+/-0.01 mg/kg/min per uU/ml) and gestational diabetic pregnancies (0. 04+/-0. 01 mg/kg/min per uU/ml) as compared to non-pregnant controls (0.11+/-0.02 mg/kg/min per uU/ml) (p\u3c0.05). Neither glucagon nor growth hormone were found to be significantly different between the normal pregnant or gestational diabetic groups. These studies suggest that normal pregnancy is indeed characterized by a tissue insensitivity to insulin and that glucose tolerance (defined in this study as the rate of glucose uptake) in normal pregnancy is primarily related to the degree of compensatory hyperinsulinism. However, this increased compensatory insulin secretion appears to be absent in gestational diabetic women, thereby contributing to the deterioration of glucose tolerance observed in these women

Improved simulation of extreme precipitation in a high-resolution atmosphere model

Climate models often underestimate the magnitude of extreme precipitation. We compare the performance of a high-resolution (∼0.25°) time-slice atmospheric simulation (1979–2005) of the Community Earth System Model 1.0 in representing daily extreme precipitation events against those of the same model at lower resolutions (∼1° and 2°). We find significant increases in the simulated levels of daily extreme precipitation over Europe, the United States, and Australia. In many cases the increase in high percentiles (>95th) of daily precipitation leads to better agreement with observational data sets. For lower percentiles, we find that increasing resolution does not significantly increase values of simulated precipitation. We argue that the reduced biases mainly result from the higher resolution models resolving more key physical processes controlling heavy precipitation. We conclude that while high resolution is vital for accurately simulating extreme precipitation, considerable biases remain at the highest available model resolutions