ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Unknown
    Gembloux (Belgique) : Presses Agronomiques de Gembloux, Liege University
    Keywords: Périurbain ; Périurbansiation ; Villes du Sud
    Description / Table of Contents: Nous assistons actuellement au peuplement des zones périurbaines de la planète par des centaines de millions d’individus. Cette évolution pose de redoutables problèmes et des difficultés inédites pour les politiques publiques. Si les effets de la périurbanisation sont relativement bien connus dans les pays du Nord, les analyses dédiées aux pays du Sud sont bien moins développées. L’ouvrage « Territoires périurbains : développement, enjeux et perspectives dans les pays du Sud » permet de lever un coin du voile sur cette problématique et sur les grands défis que la périurbanisation pose pour le Sud en général et pour l’Afrique centrale en particulier. L’ouvrage débute en cherchant à clarifier ce qu’il faut exactement entendre par « territoire périurbain ». À la suite de cette mise en contexte, il se poursuit par cinq parties organisées autour des problématiques des ressources naturelles, de la sécurité alimentaire, de la santé publique, des services publics et de l’aménagement des territoires. Pour chacune de ces problématiques, des chercheurs spécialisés issus de disciplines variées apportent des contributions qui, tout en soulignant l’ampleur des défis, permettent la mise en avant de solutions innovantes pour améliorer la gouvernance et le bien-être des populations. Cet ouvrage s’adresse d’abord aux chercheurs préoccupés par les défis du développement. En parallèle, par les pistes pour l’action publique qu’il esquisse, il ne manquera pas d’également intéresser les décideurs et les praticiens qui opèrent dans le contexte des territoires périurbains des pays du Sud.
    Pages: Online-Ressource (304 Seiten)
    ISBN: 9782870161364
    Language: English
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Environmental and ecological statistics 6 (1999), S. 211-223 
    ISSN: 1573-3009
    Keywords: Gini coefficient ; coefficient of variation ; partially ordered sets ; adapted Gini coefficient ; intrinsic diversity profiles ; k-dominance curves.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Problems with the notion of evenness, such as ambiguity, proliferation of indices, choice of indices, etc. can be overcome by a more fundamental, mathematical approach. We show that the Lorenz curve is an adequate representation of evenness. The corresponding Lorenz order induces a partial order in the set of equivalent abundance vectors. Also diversity can adequately be studied through a partial order and represented by a curve derived from the classical Lorenz curve. This curve is known as the intrinsic diversity profile (or k-dominance curve) and was introduced by Patil and Taillie (1979) and Lambshead et al. (1981).
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 1588-2861
    Source: Springer Online Journal Archives 1860-2000
    Topics: Information Science and Librarianship , Nature of Science, Research, Systems of Higher Education, Museum Science
    Notes: Abstract It is shown how Bradford curves, i.e. cumulative rank-frequency functions, as used in informetrics, can describe the fragment size distribution of percolation models. This interesting fact is explained by arguing that some aspects of percolation can be interpreted as a model for the success-breeds-success or cumulative advantage phenomenon. We claim, moreover, that the percolation model can be used as a model to study (generalised) bibliographies. This article shows how ideas and techniques studied and developed in informetrics and scientometrics can successfully be applied in other fields of science, and vice versa.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    ISSN: 1352-8661
    Keywords: heart ; ejection fraction ; MR studies ; volume
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Physics
    Notes: Abstract To evaluate the reproducibility of measurements of left ventricular (LV) dimensions, function, and myocardial mass, segmentedk-space gradient-recalled-echo (GRE) magnetic resonance (MR) imaging was performed on two occasions on 12 healthy volunteers. To compare the MR data, all volunteers underwent a two-dimensional echocardiography with determination of LV dimensions and function. The left ventricle was imaged during breath-hold by consecutive, contiguous short-axis views at end-diastole and end-systole. An average of eight short-axis views was needed to encompass the whole left ventricle. This fast MR sequence limited the total acquisition time to 12 min. LV volumes and masses were calculated after manual delineation of epicardial and endocardial surfaces by two observers in a blinded fashion. Interstudy variability varied between 4.1% and 10.3% for LV end-diastolic volume and end-systolic volume, respectively. Differences in interobserver variability were smaller and varied between 3.6% and 7.3% for LV ejection fraction and end-diastolic volume, respectively. Intraobserver variabilities ranged between 2.0% and 7.0% for LV ejection fraction and end-systolic volume, respectively. These variability percentages agree very well with other studies in literature using other MR sequences. No significant differences in LV dimensions or function were found between MR imaging and echocardiography. In conclusion, this MR sequence allows fast and reproducible LV quantification.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    ISSN: 1352-8661
    Keywords: magnetic resonance ; left ventricular function ; myocardium
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Physics
    Notes: Abstract Myocardial tagging with magnetic resonance (MR) imaging offers unique possibilities for noninvasive left ventricular (LV) strain analysis. True three-dimensional strain analysis can be achieved with tags implemented in cardiac short axis and long axis images. Spin-echo (SE) techniques have been used for these studies. However, this approach is time-consuming: images at different phases of the cardiac cycle have to be obtained in successive measurements and hence the total number of measurements equals the number of time frames. Moreover, the images are often degraded by flow and motion artifacts. The purpose of this study was to optimize a faster and more robust MR tagging sequence for use on a clinical whole-body 1 T MR system with optimal persistence of the tags during the entire cardiac cycle. The tagging pulses were implemented in gradient-recalled-echo (GRE) sequences and compared to SE-based acquisitions. The effects of the use of flow-compensating gradients, the excitation angles, and the angles of the saturation pulses have been studied with MR signal simulations and in comparative measurements in volunteers. GRE acquisitions with flow-compensating gradients are robust techniques for myocardial tagging acquisitions. Use of optimized flip angles and saturation pulses can significantly improve delineation of the tag and can be used up to at least 700 ms after the R-wave. Therefore, LV tagging with GRE acquisitions using optimized MR parameters is a robust and promising technique.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Publication Date: 2024-04-13
    Description: Trees structure the Earth's most biodiverse ecosystem, tropical forests. The vast number of tree species presents a formidable challenge to understanding these forests, including their response to environmental change, as very little is known about most tropical tree species. A focus on the common species may circumvent this challenge. Here we investigate abundance patterns of common tree species using inventory data on 1,003,805 trees with trunk diameters of at least 10 cm across 1,568 locations1-6 in closed-canopy, structurally intact old-growth tropical forests in Africa, Amazonia and Southeast Asia. We estimate that 2.2%, 2.2% and 2.3% of species comprise 50% of the tropical trees in these regions, respectively. Extrapolating across all closed-canopy tropical forests, we estimate that just 1,053 species comprise half of Earth's 800 billion tropical trees with trunk diameters of at least 10 cm. Despite differing biogeographic, climatic and anthropogenic histories7, we find notably consistent patterns of common species and species abundance distributions across the continents. This suggests that fundamental mechanisms of tree community assembly may apply to all tropical forests. Resampling analyses show that the most common species are likely to belong to a manageable list of known species, enabling targeted efforts to understand their ecology. Although they do not detract from the importance of rare species, our results open new opportunities to understand the world's most diverse forests, including modelling their response to environmental change, by focusing on the common species that constitute the majority of their trees.
    Keywords: Multidisciplinary ; ABUNDANCE DISTRIBUTIONS ; ALPHA-DIVERSITY ; PLANT DIVERSITY ; FORESTS ; BIOMASS
    Repository Name: National Museum of Natural History, Netherlands
    Type: info:eu-repo/semantics/article
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    Publication Date: 2011-03-08
    Description: In this paper, the full wave simulation of a 2-D Luneburg lens is reported, using the Multilevel Fast Multipole Algorithm (MLFMA). To stabilize the MLFMA at low frequencies, it is augmented with a normalized plane-wave method, yielding a fully broadband solver. To test the proposed method, the Luneburg lens is partitioned into concentric shells with a constant permittivity, resulting in a complex simulation target that consists of multiple embedded dielectric objects. The numerical results are in good agreement with the analytical solutions for both the continuous and discretized lens.
    Print ISSN: 0048-6604
    Electronic ISSN: 1944-799X
    Topics: Geosciences , Physics
    Published by Wiley on behalf of American Geophysical Union (AGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    Publication Date: 2014-12-01
    Description: In the context of the reduction of greenhouse gas emissions caused by deforestation and forest degradation (the REDD+ program), optical very high resolution (VHR) satellite images provide an opportunity to characterize forest canopy structure and to quantify aboveground biomass (AGB) at less expense than methods based on airborne remote sensing data. Among the methods for processing these VHR images, Fourier textural ordination (FOTO) presents a good method to detect forest canopy structural heterogeneity and therefore to predict AGB variations. Notably, the method does not saturate at intermediate AGB values as do pixelwise processing of available space borne optical and radar signals. However, a regional-scale application requires overcoming two difficulties: (1) instrumental effects due to variations in sun?scene?sensor geometry or sensor-specific responses that preclude the use of wide arrays of images acquired under heterogeneous conditions and (2) forest structural diversity including monodominant or open canopy forests, which are of particular importance in Central Africa. In this study, we demonstrate the feasibility of a rigorous regional study of canopy texture by harmonizing FOTO indices of images acquired from two different sensors (Geoeye-1 and QuickBird-2) and different sun?scene?sensor geometries and by calibrating a piecewise biomass inversion model using 26 inventory plots (1 ha) sampled across very heterogeneous forest types. A good agreement was found between observed and predicted AGB (residual standard error [RSE] = 15%; R2 = 0.85; P 〈 0.001) across a wide range of AGB levels from 26 Mg/ha to 460 Mg/ha, and was confirmed by cross validation. A high-resolution biomass map (100-m pixels) was produced for a 400-km2 area, and predictions obtained from both imagery sources were consistent with each other (r = 0.86; slope = 1.03; intercept = 12.01 Mg/ha). These results highlight the horizontal structure of forest canopy as a powerful descriptor of the entire forest stand structure and heterogeneity. In particular, we show that quantitative metrics resulting from such textural analysis offer new opportunities to characterize the spatial and temporal variation of the structure of dense forests and may complement the toolbox used by tropical forest ecologists, managers or REDD+ national monitoring, reporting and verification bodies. # doi:10.1890/13-1574.1
    Print ISSN: 1051-0761
    Electronic ISSN: 1939-5582
    Topics: Biology
    Published by Wiley on behalf of The Ecological Society of America (ESA).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    Publication Date: 2019
    Description: Côte d’Ivoire’s rural areas adjacent to the state-owned areas of the southern half of the country, such as classified forests, are experiencing significant migratory flows due to their agricultural potential. The population movements in these rural areas have changed the rural landscape. The general objective of this study was to identify the peasant innovations implemented in these rural areas adjacent to the state’s forest domains in a context of land saturation caused by migratory flows. This objective was elucidated from the case of the classified forest of Haut-Sassandra (CFHS). To achieve this, surveys were conducted in 11 villages on the periphery of the FCHS to determine the profile of planters and the main crops grown. Subsequently, floristic inventories were carried out on farms to analyse the diversity of associated species. Analyses showed that the rural populations of the CFHS are mainly composed of Allochthones (64%). Four innovative production systems were identified: a cashew-based production system, a cocoa-based production system, a coffee-based production system and a coffee- and cocoa-based production system. These farmer innovations based on agroforestry practices make it possible to restore impoverished lands and fight against climatic hazards. Consequently, these local practices deserve to be popularised in areas of strong land pressure as strategies to overcome the shortage of arable land and fluctuating prices of agricultural production.
    Electronic ISSN: 2071-1050
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Published by MDPI
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    Publication Date: 2013-10-01
    Print ISSN: 0022-5193
    Electronic ISSN: 1095-8541
    Topics: Biology
    Published by Elsevier
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...