Analysis of low altitude atmospheric turbulence data measured in flight

All three components of turbulence were measured simultaneously in flight at each wing tip of a Beech D-18 aircraft. The flights were conducted at low altitude, 30.5 - 61.0 meters (100-200 ft.), over water in the presence of wind driven turbulence. Statistical properties of flight measured turbulence were compared with Gaussian and non-Gaussian turbulence models. Spatial characteristics of the turbulence were analyzed using the data from flight perpendicular and parallel to the wind. The probability density distributions of the vertical gusts show distinctly non-Gaussian characteristics. The distributions of the longitudinal and lateral gusts are generally Gaussian. The power spectra compare in the inertial subrange at some points better with the Dryden spectrum, while at other points the von Karman spectrum is a better approximation. In the low frequency range the data show peaks or dips in the power spectral density. The cross between vertical gusts in the direction of the mean wind were compared with a matched non-Gaussian model. The real component of the cross spectrum is in general close to the non-Gaussian model. The imaginary component, however, indicated a larger phase shift between these two gust components than was found in previous research

Development and application of a non-Gaussian atmospheric turbulence model for use in flight simulators

A method is described for generating time histories which model the frequency content and certain non-Gaussian probability characteristics of atmospheric turbulence including the large gusts and patchy nature of turbulence. Methods for time histories using either analog or digital computation are described. A STOL airplane was programmed into a 6-degree-of-freedom flight simulator, and turbulence time histories from several atmospheric turbulence models were introduced. The pilots' reactions are described

A non-gaussian model of continuous atmospheric turbulence for use in aircraft design

A non-Gaussian model of atmospheric turbulence is presented and analyzed. The model is restricted to the regions of the atmosphere where the turbulence is steady or continuous, and the assumptions of homogeneity and stationarity are justified. Also spatial distribution of turbulence is neglected, so the model consists of three independent, stationary stochastic processes which represent the vertical, lateral, and longitudinal gust components. The non-Gaussian and Gaussian models are compared with experimental data, and it is shown that the Gaussian model underestimates the number of high velocity gusts which occur in the atmosphere, while the non-Gaussian model can be adjusted to match the observed high velocity gusts more satisfactorily. Application of the proposed model to aircraft response is investigated, with particular attention to the response power spectral density, the probability distribution, and the level crossing frequency. A numerical example is presented which illustrates the application of the non-Gaussian model to the study of an aircraft autopilot system. Listings and sample results of a number of computer programs used in working with the model are included

ANTISICKLING ACTIVITY EVALUATION OF FRACTIONS OBTAINED FROM WHOLE EXTRACTS OF NEWBOULDIA LAEVIS P. BEAUV (BIGNONIACEAE)

Objective: This study aims to evaluate the fractions from whole extracts of roots and stem barks of Newbouldia laevis and their effect on sickling. Methods: Hydroethanolic extracts of stem barks and roots of Newbouldia laevis were fractionated by the technics of cold precipitation in ethanol. The fractions obtained after phytochemical screening were subjected to Emmel test to evaluate their anti-sickling activity. Active fractions were tested for DPPH and AAPH assay (AAPH induced membrane lipoperoxidation and evaluation of reduction of hemolysis). Results: Two fractions were obtained from each whole extract: supernatant and pellet fractions. Supernatants fractions obtained from whole roots barks extract and stem barks extract at a concentration of 30 mg/ml reduced sickling up respectively to 7% and 10% against 86% for the control. Pellets fractions obtained from the both extracts induced coagulation of SS blood at 30 mg/ml against 86% for the control. Conclusion: Supernatants fractions of hydroethanolic whole extract of roots and stem backs of Newbouldia laevis promise as the potential source of active molecules against sickle cell disease

Local biodiversity is higher inside than outside terrestrial protected areas worldwide

Protected areas are widely considered essential for biodiversity conservation. However, few global studies have demonstrated that protection benefits a broad range of species. Using a new global biodiversity database with unprecedented geographic and taxonomic coverage, we compare four biodiversity measures at sites sampled in multiple land uses inside and outside protected areas. Globally, species richness is 10.7% higher and abundance 14.5% higher in samples taken inside protected areas compared to samples taken outside, but neither rarefaction-based richness nor endemicity differ significantly. Importantly, we show that the positive effects of protection are mostly attributable to differences in land use between protected and unprotected sites. Nonetheless, even within some human-dominated land uses, species richness and abundance are higher in protected sites. Our results reinforce the global importance of protected areas but suggest that protection does not consistently benefit species with small ranges or increase the variety of ecological niches

Simulation der Strahlreinigung: Diffusionsmodell für quellbare Verschmutzungen

Ein im Hinblick auf geringen Berechnungsaufwand entwickeltes, physikalisch-numerisches Simulationsmodell für Reinigungsvorgänge durch diffusives Auflösen oder kohäsives Trennen kleiner Verschmutzungsteilchen wird vorgestellt und validiert. Die Strömungs- berechnung auf Grundlage der Reynolds-gemittelten Navier Stokes Gleichungen (RANS) und die Berechnung des Verschmutzungstransports mittels eines instationären RANS- Ansatzes erfolgen entkoppelt. Das Verschmutzungsverhalten ist als transiente Dirichlet-Randbedingung modelliert, deren Parameter aus Laborexperimenten in einer ebenen Kanalströmung bestimmt werden. Die Validierung erfolgt für die Konfiguration eines senkrecht auftreffenden, kohärenten Flüssigkeitsstrahls für den Düsendurchmesser 1,69 mm und Drücke in der Düse zwischen 1,5 und 5 bar, d.h. Reynolds-Zahlen zwischen 17700 und 55600. Gemessen an der im Vergleich zu den Parametrierungsexperimenten um mehrere Größenordnungen höheren Wandschubspannung, der Einfachheit des Modells und der Komplexität des Testfalls wird eine sehr gute Übereinstimmung der simulierten Reinigungszeiten mit den Messwerten erreicht. Die angestrebte Skalierbarkeit sowie die Übertragbarkeit des Modells auf andere Strömungskonfigurationen sind somit gegeben

Measuring Terrestrial Area of Habitat (AOH) and Its Utility for the IUCN Red List

The International Union for Conservation of Nature (IUCN) Red List of Threatened Species includes assessment of extinction risk for 98 512 species, plus documentation of their range, habitat, elevation, and other factors. These range, habitat and elevation data can be matched with terrestrial land cover and elevation datasets to map the species’ area of habitat (AOH; also known as extent of suitable habitat; ESH). This differs from the two spatial metrics used for assessing extinction risk in the IUCN Red List criteria: extent of occurrence (EOO) and area of occupancy (AOO). AOH can guide conservation, for example, through targeting areas for field surveys, assessing proportions of species’ habitat within protected areas, and monitoring habitat loss and fragmentation. We recommend that IUCN Red List assessments document AOH wherever practical

Changing how Earth System Modelling is done to provide more useful information for decision making, science and society

New details about natural and anthropogenic processes are continually added to models of the Earth system, anticipating that the increased realism will increase the accuracy of their predictions. However, perspectives differ about whether this approach will improve the value of the information the models provide to decision makers, scientists, and societies. The present bias toward increasing realism leads to a range of updated projections, but at the expense of uncertainty quantification and model tractability. This bias makes it difficult to quantify the uncertainty associated with the projections from any one model or to the distribution of projections from different models. This in turn limits the utility of climate model outputs for deriving useful information such as in the design of effective climate change mitigation and adaptation strategies or identifying and prioritizing sources of uncertainty for reduction. Here we argue that a new approach to model development is needed, focused on the delivery of information to support specific policy decisions or science questions. The central tenet of this approach is the assessment and justification of the overall balance of model detail that reflects the question posed, current knowledge, available data, and sources of uncertainty. This differs from contemporary practices by explicitly seeking to quantify both the benefits and costs of details at a systemic level, taking into account the precision and accuracy with which predictions are made when compared to existing empirical evidence. We specify changes to contemporary model development practices that would help in achieving this goal.</jats:p

Quantitative trait loci conferring grain mineral nutrient concentrations in durum wheat 3 wild emmer wheat RIL population

Mineral nutrient malnutrition, and particularly deficiency in zinc and iron, afflicts over 3 billion people worldwide. Wild emmer wheat, Triticum turgidum ssp. dicoccoides, genepool harbors a rich allelic repertoire for mineral nutrients in the grain. The genetic and physiological basis of grain protein, micronutrients (zinc, iron, copper and manganese) and macronutrients (calcium, magnesium, potassium, phosphorus and sulfur) concentration was studied in tetraploid wheat population of 152 recombinant inbred lines (RILs), derived from a cross between durum wheat (cv. Langdon) and wild emmer (accession G18-16). Wide genetic variation was found among the RILs for all grain minerals, with considerable transgressive effect. A total of 82 QTLs were mapped for 10 minerals with LOD score range of 3.2–16.7. Most QTLs were in favor of the wild allele (50 QTLs). Fourteen pairs of QTLs for the same trait were mapped to seemingly homoeologous positions, reflecting synteny between the A and B genomes. Significant positive correlation was found between grain protein concentration (GPC), Zn, Fe and Cu, which was supported by significant overlap between the respective QTLs, suggesting common physiological and/or genetic factors controlling the concentrations of these mineral nutrients. Few genomic regions (chromosomes 2A, 5A, 6B and 7A) were found to harbor clusters of QTLs for GPC and other nutrients. These identified QTLs may facilitate the use of wild alleles for improving grain nutritional quality of elite wheat cultivars, especially in terms of protein, Zn and Fe