Lewis hybrid computing system, users manual

The Lewis Research Center's Hybrid Simulation Lab contains a collection of analog, digital, and hybrid (combined analog and digital) computing equipment suitable for the dynamic simulation and analysis of complex systems. This report is intended as a guide to users of these computing systems. The report describes the available equipment' and outlines procedures for its use. Particular is given to the operation of the PACER 100 digital processor. System software to accomplish the usual digital tasks such as compiling, editing, etc. and Lewis-developed special purpose software are described

Tadeusz Buksiński, Prawo a władza polityczna, Wyd. Naukowe IF UAM, Poznań 2009, ss. 308.

Tadeusz Buksiński, Prawo a władza polityczna, Wyd. Naukowe IF UAM, Poznań 2009, ss. 308

Środki masowego przekazu w kulturze współczesnej - informacja i oświecenie czy manipulacja?

In the paper, the author formulates the thesis that in our times the role of journalism has been lost as the medium of informing about events, the popularisation of knowledge and forming positive cultural patterns. This happened as a result of a departure from a culture that refers to values. At present, the mass media create a consumerist culture, focused on short-term interests and living an ordinary life. This allows them to manipulate society for the sake of the interests of different groups. In order to overcome this state of affairs, which is unfavourable for society, it is necessary to return to the ideals of the Enlightenment and a culture appealing to values.W tekście autorka formułuje tezę, że współcześnie została zatracona rola dziennikarstwa polegająca na przekazie informacji o wydarzeniach oraz popularyzacji wiedzy i formułowaniu pozytywnych wzorców kulturowych. Stało się to na skutek odejścia od kultury odwołującej się do wartości. Współczesne środki masowego przekazu kreują kulturę konsumpcyjną, nastawioną na doraźne interesy i życie potocznością. Umożliwia ona w imię interesów różnych grup manipulowanie społeczeństwem. Warunkiem przezwyciężenia tego niekorzystnego dla społeczeństwa stanu rzeczy jest powrót do ideałów Oświecenia i kultury odwołującej się do wartości

Darwin’s wind hypothesis: does it work for plant dispersal in fragmented habitats?

Using the wind-dispersed plant Mycelis muralis, we examined how landscape fragmentation affects variation in seed traits contributing to dispersal. Inverse terminal velocity (Vt−1) of field-collected achenes was used as a proxy for individual seed dispersal ability. We related this measure to different metrics of landscape connectivity, at two spatial scales: in a detailed analysis of eight landscapes in Spain and along a latitudinal gradient using 29 landscapes across three European regions. In the highly patchy Spanish landscapes, seed Vt−1 increased significantly with increasing connectivity. A common garden experiment suggested that differences in Vt−1 may be in part genetically based. The Vt−1 was also found to increase with landscape occupancy, a coarser measure of connectivity, on a much broader (European) scale. Finally, Vt−1 was found to increase along a south–north latitudinal gradient. Our results for M. muralis are consistent with ‘Darwin’s wind dispersal hypothesis’ that high cost of dispersal may select for lower dispersal ability in fragmented landscapes, as well as with the ‘leading edge hypothesis’ that most recently colonized populations harbour more dispersive phenotypes.

Main results of the Ouabain and Adducin for Specific Intervention on Sodium in Hypertension Trial (OASIS-HT): a randomized placebo-controlled phase-2 dose-finding study of rostafuroxin

Background. The Ouabain and Adducin for Specific Intervention on Sodium in Hypertension (OASIS-HT) Trial was a phase 2 dose-finding study of rostafuroxin, a digitoxygenin deivative, which selectively antagonizes the effects of endogenous ouabain (EO) on Na+,K+-ATPase and mutated adducin. Rostafuroxin lowered blood pressure (BP) in some animal models and in humans. Methods. OASIS-HT consisted of 5 concurrently running double-blind cross-over studies. After 4 weeks without treatment, 435 patients with uncomplicated systolic hypertension (140-169 mm Hg) were randomized to rostafuroxin (0.05, 0.15, 0.5, 1.5 or 5.0 mg/d) or matching placebo, each treatment period lasting 5 weeks. The primary endpoint was the reduction in systolic office BP. Among the secondary endpoints were diastolic office BP, 24 h ambulatory BP, plasma EO concentration and renin activity, 24-h urinary sodium and aldosterone excretion, and safety. ANOVA considered treatment sequence (fixed effect), subjects nested within sequence (random), period (fixed), and treatment (fixed). Results. Among 410 analyzable patients (40.5% women; mean age, 48.4 years), the differences in the primary endpoint (rostafuroxin minus placebo) ranged from -0.18 mm Hg (P=0.90) on 0.15 mg/d rostafuroxin to 2.72 mm Hg (P=0.04) on 0.05 mg/d. In the 5 dosage arms combined, the treatment effects averaged 1.30 mm Hg (P=0.03) for systolic office BP; 0.70 mm Hg (P=0.08) for diastolic office BP; 0.36 mm Hg (P=0.49) for 24-h systolic BP; and 0.05 mm Hg (P=0.88) for 24-h diastolic BP. In the 2 treatment groups combined, systolic (-1.36 mm Hg) and diastolic (-0.97 mm Hg) office BPs decreased from week 5 to 10 (P for period effect ≤=0.028), but carry-over effects were not significant (P≥=0.11). All other endpoints were not different on rostafuroxin and placebo. Minor side-effects occurred with similarly low frequency on rostafuroxin and placebo. Conclusions. In 5 concurrently running double-blind cross-over studies rostafuroxin did not reduce BP at any dose. Trial Registration: NCT00415038 http://www.clinicaltrials.gov)

Increasing Tephra Deposition in Northeastern North America Points to Atmospheric Circulation Changes at the Early Mid Holocene Transition

The number of cryptotephra (non-visible volcanic ash) records from northeastern North America is unique in the continent. The resulting tephrostratigraphic framework includes ash deposits sourced from volcanic arcs across the Northern Hemisphere and is an exceptional resource for correlating and dating paleoenvironmental records. It also provides an opportunity to explore more novel questions regarding the controls on ultra-distal tephra (volcanic ash >3,000 km from source) dispersal and deposition. Here, we examine temporal patterns in the tephrostratigraphy of northeastern North America to test the legitimacy of a previously noted change in ash deposition frequency at the Early Mid Holocene transition. We integrate five new cryptotephra records into the existing framework to improve its temporal and spatial extent and report further occurrences of widespread cryptotephra deposits including Mt. St. Helens We, Jala pumice, White River Ash east, Ruppert tephra, Mt. St. Helens Yn and Mazama Ash. Reexamination of the combined tephrostratigraphy using breakpoint analysis shows a significant increase in the frequency of ashfall after ca. 9,000 (7,860–9,650) cal yr BP (calendar years before C.E. 1950). We discuss this change in relation to volcanic and environmental controls of fine ash dispersal and preservation. We reject hypotheses relating to eruption frequency or depositional processes in favor of changing atmospheric transport patterns and tephra dispersal—possibly caused by the retreat of the Laurentide Ice Sheet. Our study is a novel example of how tephrostratigraphy can be used beyond traditional correlative and dating studies, in this case indicating large-scale changes in atmospheric circulation through time

Range Expansion Drives Dispersal Evolution In An Equatorial Three-Species Symbiosis

A-09-14International audienceBackground Recurrent climatic oscillations have produced dramatic changes in species distributions. This process has been proposed to be a major evolutionary force, shaping many life history traits of species, and to govern global patterns of biodiversity at different scales. During range expansions selection may favor the evolution of higher dispersal, and symbiotic interactions may be affected. It has been argued that a weakness of climate fluctuation-driven range dynamics at equatorial latitudes has facilitated the persistence there of more specialized species and interactions. However, how much the biology and ecology of species is changed by range dynamics has seldom been investigated, particularly in equatorial regions. Methodology/Principal Findings We studied a three-species symbiosis endemic to coastal equatorial rainforests in Cameroon, where the impact of range dynamics is supposed to be limited, comprised of two species-specific obligate mutualists –an ant-plant and its protective ant– and a species-specific ant parasite of this mutualism. We combined analyses of within-species genetic diversity and of phenotypic variation in a transect at the southern range limit of this ant-plant system. All three species present congruent genetic signatures of recent gradual southward expansion, a result compatible with available regional paleoclimatic data. As predicted, this expansion has been accompanied by the evolution of more dispersive traits in the two ant species. In contrast, we detected no evidence of change in lifetime reproductive strategy in the tree, nor in its investment in food resources provided to its symbiotic ants. Conclusions/Significance Despite the decreasing investment in protective workers and the increasing investment in dispersing females by both the mutualistic and the parasitic ant species, there was no evidence of destabilization of the symbiosis at the colonization front. To our knowledge, we provide here the first evidence at equatorial latitudes that biological traits associated with dispersal are affected by the range expansion dynamics of a set of interacting species

Ancient DNA from lake sediments: Bridging the gap between paleoecology and genetics

<p>Abstract</p> <p>Background</p> <p>Quaternary plant ecology in much of the world has historically relied on morphological identification of macro- and microfossils from sediments of small freshwater lakes. Here, we report new protocols that reliably yield DNA sequence data from Holocene plant macrofossils and bulk lake sediment used to infer ecological change. This will allow changes in census populations, estimated from fossils and associated sediment, to be directly associated with population genetic changes.</p> <p>Results</p> <p>We successfully sequenced DNA from 64 samples (out of 126) comprised of bulk sediment and seeds, leaf fragments, budscales, and samaras extracted from Holocene lake sediments in the western Great Lakes region of North America. Overall, DNA yields were low. However, we were able to reliably amplify samples with as few as 10 copies of a short cpDNA fragment with little detectable PCR inhibition. Our success rate was highest for sediments < 2000 years old, but we were able to successfully amplify DNA from samples up to 4600 years old. DNA sequences matched the taxonomic identity of the macrofossil from which they were extracted 79% of the time. Exceptions suggest that DNA molecules from surrounding nearby sediments may permeate or adhere to macrofossils in sediments.</p> <p>Conclusions</p> <p>An ability to extract ancient DNA from Holocene sediments potentially allows exciting new insights into the genetic consequences of long-term environmental change. The low DNA copy numbers we found in fossil material and the discovery of multiple sequence variants from single macrofossil extractions highlight the need for careful experimental and laboratory protocols. Further application of these protocols should lead to better understanding of the ecological and evolutionary consequences of environmental change.</p

Virtual Patients and Sensitivity Analysis of the Guyton Model of Blood Pressure Regulation: Towards Individualized Models of Whole-Body Physiology

Mathematical models that integrate multi-scale physiological data can offer insight into physiological and pathophysiological function, and may eventually assist in individualized predictive medicine. We present a methodology for performing systematic analyses of multi-parameter interactions in such complex, multi-scale models. Human physiology models are often based on or inspired by Arthur Guyton's whole-body circulatory regulation model. Despite the significance of this model, it has not been the subject of a systematic and comprehensive sensitivity study. Therefore, we use this model as a case study for our methodology. Our analysis of the Guyton model reveals how the multitude of model parameters combine to affect the model dynamics, and how interesting combinations of parameters may be identified. It also includes a “virtual population” from which “virtual individuals” can be chosen, on the basis of exhibiting conditions similar to those of a real-world patient. This lays the groundwork for using the Guyton model for in silico exploration of pathophysiological states and treatment strategies. The results presented here illustrate several potential uses for the entire dataset of sensitivity results and the “virtual individuals” that we have generated, which are included in the supplementary material. More generally, the presented methodology is applicable to modern, more complex multi-scale physiological models

Acidification of Forest Soil in Russia: 1893-Present

It is commonly believed that fine texture soils developed on carbonateparent material are well buffered from possible acidification. There areno data, however, documenting resistance of such soils to acidicdeposition exposure on a time scale longer than 30-40 years.In this paper we employed a rare opportunity of directly testinglong-term buffering capacity of 19th century forest soils developedon calcareous silt loam. A comparison of chemical analysis of archivedsoils with modern soils collected from the same locations ~100 yearslater indicate varying degrees of acidification of forest soils in taiga andthe forest steppe regions. Reforestation and increases in precipitationcontributed to acidification, as well as acidic deposition. The acidificationof forest soil was detected through decreases in soil pH, and changesin concentrations of exchangeable calcium and aluminum, whichcorresponded with changes in communities of soil microfauna. Althoughacidification was found at all 3 locations that were analyzed, the trendsin soil chemistry were greatest where the highest loading of acidicdeposition had taken place