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The Threshold Level Method is an approach that enables comparability across all hydrological levels. This advantage is used especially in studies on drought propagation. There are different calculation procedures for this method. The effect that the choice of a variable versus a constant threshold level method has on drought characteristics and drought propagation patterns has not been fully explored yet. Also, most drought propagation studies have analyzed modelled data, suggesting that applicability to observations be tested. We tested the Constant and the Variable Threshold Level Method for the 10th, 20th and 30th percentile on observed precipitation, streamflow, and groundwater data from Germany, and compared drought characteristics and drought propagation patterns by means of statistical analysis and synoptic assessment. The characteristic effects of choosing a variable versus a constant threshold are: (1) a substantial increase in short droughts, (2) a moderate decrease in intermediate droughts and (3) a minor increase in long droughts. Furthermore, in slow-reacting lowland catchments, theoretical propagation characteristics could mostly be confirmed. In faster-reacting upland catchments, this was not always the case and considerable differences arose. Sources of ambiguity were predominantly groundwater in lowlands and streamflow in the mountainous catchments. In conclusion, there is potential of diverging inference from the same data, depending on the chosen methodology.

This study analyses trends of mean (Tm), maximum (Tx), minimum (Tn), dew point (Td), and wet-bulb temperatures (Tw) on an annual, seasonal, and monthly time scale over Spain during the period 1981–2010. The main purpose was to determine how temperature and humidity changes are impacting on Tw, which is probably a better measure of climate change than temperature alone. In this study, 43 weather stations were used to detect data trends using the nonparametric Mann-Kendall test and the Sen method to estimate the slope of trends. Significant linear trends observed for Tm, Tx, and Tn versus year were 56, 58, and 47 % of the weather stations, respectively, with temperature ranges between 0.2 and 0.4 °C per decade. The months with bigger trends were April, May, June, and July with the highest trend for Tx. The spatial behaviour of Td and Tw was variable, with various locations showing trends from −0.6 to +0.3 °C per decade for Td and from −0.4 to +0.5 °C per decade for Tw. Both Td and Tw showed negative trends for July, August, September, November, and December. Comparing the trends versus time of each variable versus each of the other variables exhibited poor relationships, which means you cannot predict the trend of one variable from the trend of another variable. The trend of Tx was not related to the trend of Tn. The trends of Tx, Tm, and Tn versus time were unrelated to the trends versus time of either Td or Tw. The trend of Tw showed a high coefficient of determination with the trend of Td with an annual value of R2 = 0.86. Therefore, the Tw trend is more related to changes in humidity than temperature.

This study is aimed at analyzing the difference of using fixed weight aggregate inventory to sales ratios rather than “traditional”, that is, variable weighted, aggregated inventory to sales ratios. It shows that interpretations of these ratios may be problematic because different aggregation methods are signaling different time trends under certain circumstances. Analyzing the inventory performance of German corporations between 1993 and 2005, we find that the total inventory to sales ratio decreased in a statistically significant extent in the majority of industry sectors during the period investigated. Considering the effects of using fixed aggregation weights on our results, some changes concerning significance of results occur. The additional use of fixed aggregation weights is helpful because it isolates any trends observed in the aggregated inventory to sales ratio series to fluctuations in the underlying (sub) sectors’ inventory to sales ratio, not shifts in the composition of the aggregate.

Fixed-rate versions of rule-consequentialism and rule-utilitarianism evaluate rules in terms of the expected net value of one particular level of social acceptance, but one far enough below 100% social acceptance to make salient the complexities created by partial compliance. Variable-rate versions of rule-consequentialism and rule-utilitarianism instead evaluate rules in terms of their expected net value at all different levels of social acceptance. Brad Hooker has advocated a fixed-rate version. Michael Ridge has argued that the variable-rate version is better. The debate continues here. Of particular interest is the difference between the implications of Hooker's and Ridge's rules about doing good for others.

Stem-and-leaf displays have been widely taught since John W. Tukey publicized them energetically in the 1970s. They remain useful for many distributions of small or modest size, especially for showing fine structure such as digit preference. Stata's implementation stem produces typed text displays and has some inevitable limitations, especially for comparison of two or more displays. One can re-create stem-and-leaf displays with a few basic Stata commands as scatterplots of stem variable versus position on line with leaves shown as marker labels. Comparison of displays then becomes easy and natural using scatter, by(). Back-to-back presentation of paired displays is also possible. I discuss variants on standard stem-and-leaf displays in which each distinct value is a stem, each distinct value is its own leaf, or axes are swapped. The problem shows how one can, with a few lines of Stata, often produce standard graph forms from first principles, allowing in turn new variants. I also present a new program, stemplot, as a convenience tool.

SUMMARYCertain tiger moths (Arctiidae) defend themselves against bats by phonoresponding to their echolocation calls with trains of ultrasonic clicks. The dogbane tiger moth, Cycnia tenera, preferentially phonoresponds to the calls produced by attacking versus searching bats, suggesting that it either recognizes some acoustic feature of this phase of the bat's echolocation calls or that it simply reacts to their increased power as the bat closes. Here, we used a habituation/generalization paradigm to demonstrate that C. tenera responds neither to the shift in echolocation call frequencies nor to the change in pulse duration that is exhibited during the bat's attack phase unless these changes are accompanied by either an increase in duty cycle or a decrease in pulse period. To separate these features, we measured the moth's phonoresponse thresholds to pulsed stimuli with variable versus constant duty cycles and demonstrate that C. tenerais most sensitive to echolocation call periods expressed by an attacking bat. We suggest that, under natural conditions, C. tenera identifies an attacking bat by recognizing the pulse period of its echolocation calls but that this feature recognition is influenced by acoustic power and can be overridden by unnaturally intense sounds.

The role of the equation of state for a perfectly conducting, relativistic magnetized fluid is the main subject of this work. The ideal constant $\Gamma$-law equation of state, commonly adopted in a wide range of astrophysical applications, is compared with a more realistic equation of state that better approximates the single-specie relativistic gas. The paper focus on three different topics. First, the influence of a more realistic equation of state on the propagation of fast magneto-sonic shocks is investigated. This calls into question the validity of the constant $\Gamma$-law equation of state in problems where the temperature of the gas substantially changes across hydromagnetic waves. Second, we present a new inversion scheme to recover primitive variables (such as rest-mass density and pressure) from conservative ones that allows for a general equation of state and avoids catastrophic numerical cancellations in the non-relativistic and ultrarelativistic limits. Finally, selected numerical tests of astrophysical relevance (including magnetized accretion flows around Kerr black holes) are compared using different equations of state. Our main conclusion is that the choice of a realistic equation of state can considerably bear upon the solution when transitions from cold to hot gas (or viceversa) are present. Under these circumstances, a polytropic equation of state can significantly endanger the solution., Comment: 14 pages, 14 figures

International audience; The aim of this study was to investigate the metabolic responses to variable versus constant-intensity (CI) during 20-km cycling on subsequent 5-km running performance. Ten triathletes, not only completed one incremental cycling test to determine maximal oxygen uptake and maximal aerobic power (MAP), but also three various cycle-run (C–R) combinations conducted in outdoor conditions. During the C–R sessions, subjects performed first a 20-km cycletime trial with a freely chosen intensity (FCI, ~80% MAP) followed by a 5-km run performance. Subsequently, triathletes were required to perform in a random order, two C–R sessions including either a CI, corresponding to the mean power of FCI ride, or a variable-intensity (VI) during cycling with power changes ranging from 68 to 92% MAP, followed immediately by a 5-km run. Metabolic responses and performances were measured during the C–R sessions. Running performance was significantly improved after CI ride (1118 ± 72 s) compared to those after FCI ride (1134 ± 64 s) or VI ride (1168 ± 73 s) despite similar metabolic responses and performances reported during the three cycling bouts. Moreover, metabolic variables were not significantly different between the run sessions in our triathletes. Given the lack of significant differences in metabolic responses between the C–R sessions, the improvement in running time after FCI and CI rides compared to VI ride suggests that other mechanisms, such as changes in neuromuscular activity of peripheral skeletal muscle or muscle fatigue, probably contribute to the influence of power output variation on subsequent running performance.

This paper measures the pass-through of trade costs into U.S. import prices by using actual data on duties/tariffs and freight-related costs. The key innovation is to decompose the indirect effects of trade costs (on prices) into the effects on markups, quality and productivity while measuring/interpreting the pass-through of trade costs into welfare. Robust to the consideration of variable versus constant markups, there is evidence for incomplete pass-through, mostly due to the negative indirect effects of trade costs on marginal costs, suggesting that lower trade costs are associated with imports that have higher marginal costs; markups are affected relatively less. When the effects of trade costs on marginal costs are further decomposed into their components, the positive contribution of quality dominates in all cases, followed by the negative effects of productivity, suggesting that lower trade costs are associated with higher-quality imports that have been produced with lower productivity.

In this paper we study optimal harvesting of the Norwegian spring-spawning herring stock. The biological model is described by a discrete time age-structured model. The optimal harvesting patterns are studied numerically and the results show that when using a linear cost function and constant price in the optimisation model, the optimal harvesting pattern is pulse fishing. However, optimal constant fishing effort gives only slightly lower profit. Moreover, when price is made responsive to harvest the optimal harvesting strategy is substantially smoothed.

In this paper we present a new technique to solve Quantified Boolean Formulas (QBF). Our technique applies the idea of dynamic partitioning to QBF solvers. Dynamic partitioning has previously been utilized in #SAT solvers that count the number of models of a propositional formula. One of the main differences with the #SAT case comes from the solution learning techniques employed in search based QBF solvers. Extending solution learning to a partitioning solver involves some considerable complexities which we show how to resolve. We have implemented our ideas in a new QBF solver, and demonstrate that dynamic partitioning is able to increase the performance of search based solvers, sometimes significantly. Empirically our new solver offers performance that is superior to other search based solvers and in many cases superior to nonsearch based solvers.

The effects of exposure pattern on the toxicity of acetaldehyde vapour were investigated in 4-week inhalation studies. Male rats were exposed to 500 or 150 and 110 ppm for 6 h per day/5 days per week. One group of animals was exposed without interruption, the exposure of a second group was interrupted for 1.5 h between the first and second 3-h periods, the exposure of a third group was similarly interrupted and for six 5 min periods exposure was increased sixfold. Peak exposures of up to 3000 ppm superimposed on 500 ppm acetaldehyde caused irritation and excitation, and reduced body weight gain. No such effects occurred after interrupted or uninterrupted exposure to 500 ppm acetaldehyde without peak loads. A reduced phagocytotic index of lung macrophages was found in each of the groups exposed to 500 ppm acetaldehyde, the effect being most marked in the group with superimposed peaks of 3000 ppm. Degeneration of the nasal olfactory epithelium was observed in rats uninterruptedly exposed to 500 ppm acetaldehyde. Interruption of the exposure or interruption combined with peak exposure did not visibly influence this adverse effect on the nose. No compound-related effects were seen in rats interruptedly or uninterruptedly exposed to 150 ppm acetaldehyde or interruptedly exposed to 110 ppm with peak loads of 660 ppm. As a consequence 150 ppm acetaldehyde can be considered a 'no-toxic-effect level' in male rats exposed for 6 h/day, 5 days/week, during a 4-week period. It was concluded that the interruption of daily exposure by 1.5 h exposure-free period or by the superimposition of six times 5 min peak exposure periods did not appreciably influence the nasocytotoxic potency of acetaldehyde. Furthermore for inhalation toxicity testing of irritants such as acetaldehyde the use of variable exposure patterns does not seem to produce more relevant toxicity data than the use of uninterrupted daily exposure to a fixed concentration. Chemicals/CAS: acetaldehyde, 75-07-0; Acetaldehyde, 75-07-0

The economic implications of variable grazing fees and single grazing fees on Federal lands are important considerations relative to further policy changes. Many factors must be considered when establishing fees on different grazing units. Quantity and quality of forage are only two of these factors and generally not the most important ones. Variable grazing fees will have to be implemented if the government is going to minimize the problem of having some of its land over-priced and some under-priced.