Dinámica de aguas superficiales de tres períodos continuos de Landsat; diferencias subregionales en llanuras argentinas

[EN] The Pampean region in Argentina is an extensive plain characterized by abundant shallow lakes that fulfill many environmental, ecological, and social functions. This study aims to detect the multiannual lake area changes in this region during 2001-2009 using remote sensing, including lakes as small as ≥10,000 m2 or 1 ha. Landsat scenes of the wet (2008-2009), normal (2006), and dry (2008-2009) seasons were obtained, and using remote sensing techniques, the number and area of shallow lakes were calculated. The spatiotemporal variation of shallow lakes was studied in different climate periods in eight singular subregions. Spatial associations between annual precipitation and lake number and area were analyzed through the development of a Geographic Information System (GIS) at a subregional scale. During the study period the total lake area in the Pampean region decreased by 5257.39 km2 (62 %), but each subregion showed different responses to climatic events. In seven of them, the differences between climate periods prove to be statistically significant (P>0.01). The relationship between precipitation and lake number and area revealed the domain of positive association. We conclude that climate factors play a dominant role in lake changes across the Pampean plains. However, other factors such as origin, topographic and edaphic characteristics intensify or mitigate changes in surface hydrology.[ES] La Región Pampeana en Argentina es una extensa planicie caracterizada por abundantes lagunas que cumplen numerosas funciones ambientales, ecológicas y sociales. Este estudio tiene como objetivo detectar los cambios plurianuales del área lagunar en esta región durante el período 2001-2009 utilizando la teledetección, incluidos lagos tan pequeños como ≥ 10.000 m2 o 1 ha. Se obtuvieron escenas Landsat de las estaciones húmeda (2008-2009), normal (2006) y seca (2008-2009) y, mediante técnicas de teledetección, se calculó el número y el área de las lagunas. Se estudió su variación espacio-temporal en diferentes períodos climáticos en ocho subregiones singulares. Se analizaron las correlaciones espaciales entre la precipitación anual y el número y el área de los lagos mediante el desarrollo de un Sistema de Información Geográfica (SIG). Durante el período de estudio el área total de lagos en la región pampeana disminuyó en 5.257,39  km2 (62 %), pero cada subregión mostró diferentes respuestas a los eventos climáticos. En siete de ellos, las diferencias entre periodos climáticos resultan estadísticamente significativas (P>0,01). La relación entre la precipitación con el número y área de las lagunas reveló el dominio de asociaciones positivas. Si bien el clima juega un papel dominante en los cambios en las lagunas de planicie, otros factores, como el origen, las características topográficas y edáficas, intensifican o mitigan los cambios en la hidrología superficial.Authors would like to thank the Consejo Nacional de Investigaciones Científicas y Técnicas for supporting this study. Besides, to the United States Geological Survey for supplying the information analyzed in this study. This work was carried out with the aid of a grant from the Inter-American Institute for Global Change Research (IAI) CRN3038, which is supported by the US National Science Foundation (Grant GEO-1128040)Aliaga, VS.; Piccolo, M.; Perillo, G. (2021). Surface water extent dynamics from three periods of continuous Landsat time series; subregional differences across Argentine plains. Revista de Teledetección. 0(58):131-145. http://hdl.handle.net/10251/169769OJS13114505

Il "Ciclo del Cossovo" di Milan Rakić

The essay examines one of the central themes of the work of Milan Rakić, one of the greatest exponents of Serbian Modernism: the cycle of compositions that focus on the history and current affairs of that region, which has always been disputed by Serbs and Albanians. These poems arise from Rakić’s personal experience in Kosovo, still subject to the Ottoman Empire, where he had been sent at the beginning of his diplomatic career. Of the seven poems in the cycle, five sing about the tragic destiny of that land, the cradle of Serbian religiosity; one, Na Gazi Mestanu, associates the taste for historical reenactments of Parnassi’s poetics with the passionate defense and proud exaltation of the Serbian people who in centuries-old relations with their homeland have drawn the stimulus for rebirth; the last, Legacy, the most evocative and vibrant, raises that indissoluble bond with the spiritual richness of the past as a reason for existential comfort. What the love of a woman had not been able to give to the poet is offered to him by the rediscovered communion with the historical consciousness of his own race

Coastal Wetlands: an integrated ecosystem approach

Coastal Wetlands, Second Edition: An Integrated and Ecosystem Approach provides an understanding of the functioning of coastal ecosystems and the ecological services that they provide. As coastal wetlands are under a great deal of pressure from the dual forces of rising sea levels and the intervention of human populations, both along the estuary and in the river catchment, this book covers important issues, such as the destruction or degradation of wetlands from land reclamation and infrastructures, impacts from the discharge of pollutants, changes in river flows and sediment supplies, land clearing, and dam operations

Direct Numerical Simulation of Transverse Ripples: 2. Self-Similarity, Bedform Coarsening, and Effect of Neighboring Structures

Coupled bed-flow direct numerical simulations investigating the early stages of pattern formation and bedform (ripple) interactions were examined in a previous paper (Part 1), making use of the resolved flow field. In this paper (Part 2), we compare our results to published experimental data and provide an extensive quantitative analysis of the bed using spectral analysis and two-point correlations. The effect of the mobile rippled bed on the flow structure and turbulence is investigated locally (at specific streamwise locations) and over the entire computational domain. We show that developing ripples attain a self-similar profile in both the shape and the corresponding bed shear stress. We demonstrate the importance of neighboring structures, especially upstream neighbors, on bedform dynamics in terms of the growth, decay, and speed of ripples. Finally, we examine the defect-free interactions in the later stages of bed evolution, which primarily lead to wave coarsening. Key Points Isolated ripples maintain a self-similar shape and bed shear stress profiles Bedform-bedform interactions can significantly modify bedform celerity Spectra of bed height variation suggest a Reynolds number dependenc

Direct Numerical Simulation of Transverse Ripples: 1. Pattern Initiation and Bedform Interactions

We present results of coupled direct numerical simulations between flow and a deformable bed in a horizontally periodic, turbulent open channel at a shear Reynolds number of Reτ = 180. The feedback between the temporally and spatially evolving bed and the flow is enforced via the immersed boundary method. Using the near-bed flow field, we provide evidence on the role of locally intense near-bed vortical structures during the early stages of bed formation, from the emergence of quasi-streamwise streaks to the formation of incipient bedform crestlines. Additionally, we take a new look at a number of defect-related bedform interactions, including lateral linking, defect and bedform repulsion, merging, and defect creation, and show that the underlying mechanisms, in these flow-aligned interactions, are very similar to each other. Consequently, the interactions are labeled differently depending on the geometry of interacting structures and the outcome of the interaction. In the companion paper, we compare our results to published experimental data and provide an extensive quantitative analysis of the bed, where we demonstrate the importance of neighboring structures, especially upstream neighbors, on bedform dynamics (growth/decay and speed) and wave coarsening. Video files of bed evolution are available in the supporting information. Key Points Mesoscale resolved simulations show the different mechanisms for bedform-bedform interactions to be very similar to each other Similar to laminar flows over dunes and ripples, a positive phase shift is observed between bed shear stress and topology even in mesoscale-resolved turbulent flow field Simulations match Coleman and Melville (1996) theory on bedform initiation from a flat be

Design of a high power production target for the Beam Dump Facility at CERN

The Beam Dump Facility (BDF) project is a proposed general-purpose facility at CERN, dedicated to beam dump and fixed target experiments. In its initial phase, the facility is foreseen to be exploited by the Search for Hidden Particles (SHiP) experiment. Physics requirements call for a pulsed 400 GeV/c proton beam as well as the highest possible number of protons on target (POT) each year of operation, in order to search for feebly interacting particles. The target/dump assembly lies at the heart of the facility, with the aim of safely absorbing the full high intensity Super Proton Synchrotron (SPS) beam, while maximizing the production of charmed and beauty mesons. High-Z materials are required for the target/dump, in order to have the shortest possible absorber and reduce muon background for the downstream experiment. The high average power deposited on target (305 kW) creates a challenge for heat removal. During the BDF facility Comprehensive Design Study (CDS), launched by CERN in 2016, extensive studies have been carried out in order to define and assess the target assembly design. These studies are described in the present contribution, which details the proposed design of the BDF production target, as well as the material selection process and the optimization of the target configuration and beam dilution. One of the specific challenges and novelty of this work is the need to consider new target materials, such as a molybdenum alloy (TZM) as core absorbing material and Ta2.5W as cladding. Thermo-structural and fluid dynamics calculations have been performed to evaluate the reliability of the target and its cooling system under beam operation. In the framework of the target comprehensive design, a preliminary mechanical design of the full target assembly has also been carried out, assessing the feasibility of the whole target system.Comment: 17 pages, 18 figure

Reliability and Reproducibility of Landmark Identification in Unilateral Cleft Lip and Palate Patients: Digital Lateral Vis-A-Vis CBCT-Derived 3D Cephalograms

Background: The aim of the retrospective observational study was to compare the precision of landmark identification and its reproducibility using cone beam computed tomography-derived 3D cephalograms and digital lateral cephalograms in unilateral cleft lip and palate patients. Methods: Cephalograms of thirty-one (31) North Indian children (18 boys and 13 girls) with a unilateral cleft lip and palate, who were recommended for orthodontic treatment, were selected. After a thorough analysis of peer-reviewed articles, 20 difficult-to-trace landmarks were selected, and their reliability and reproducibility were studied. These were subjected to landmark identification to evaluate interobserver variability; the coordinates for each point were traced separately by three different orthodontists (OBA, OBB, OBC). Statistical analysis was performed using descriptive and inferential statistics with paired t-tests to compare the differences measured by the two methods. Real-scale data are presented in mean ± SD. A p-value less than 0.05 was considered as significant at a 95% confidence level. Results: When comparing, the plotting of points posterior nasal spine (PNS) (p < 0.05), anterior nasal spine (ANS) (p < 0.01), upper 1 root tip (p < 0.05), lower 1 root tip (p < 0.05), malare (p < 0.05), pyriforme (p < 0.05), porion (p < 0.01), and basion (p < 0.05) was statistically significant. Conclusion: In patients with a cleft lip and palate, the interobserver identification of cephalometric landmarks was significantly more precise and reproducible with cone beam computed tomography -derived cephalograms vis-a-vis digital lateral cephalograms

In vitro effect of amifostine on haematopoietic progenitors exposed to carboplatin and non-alkylating antineoplastic drugs: haematoprotection acts as a drug-specific progenitor rescue.

We evaluated the protective ability of amifostine on peripheral blood mononuclear cell (PBMC)-derived colony-forming unit (CFU) and PB CD34+ cells which were previously exposed in vitro to etoposide, carboplatin, doxorubicin and taxotere. Amifostine pretreatment protected PBMC-derived CFU from the toxic effect of etoposide, carboplatin and taxotere. A significant detrimental effect was exerted by amifostine on the growth of doxorubicin-treated PBMC-derived CFU. Liquid cultures of PB CD34+ cells reproduced faithfully the effects observed on growth of PBMC-derived CFU and confirmed amifostine chemoprotection against etoposide and carboplatin with its detrimental effect on doxorubicin-treated progenitors. Combining the data of viable cell count, cytometric estimation of apoptosis, cell cycle and viable cell replication rate, we found that amifostine protects from etoposide and carboplatin toxicity mainly through a mechanism of cell rescue. Conversely, the detrimental effect of amifostine on the growth of doxorubicin-treated PB CD34+ cells is apparently due to an increased G2/M arrest. In conclusion, amifostine protects haematopoietic progenitors from etoposide, carboplatin and taxotere. Progenitor rescue is the mechanism through which amifostine reduced etoposide and carboplatin toxicity

Bedform dynamics from coupled bed-flow direct numerical simulations

We present results of time-evolving coupled direct numerical simulations between an erodible bed and an overlying pressure-driven, turbulent flow field. A total of 6 simulations are considered, the details of which are shown in Table 1. The numerical setup consists of a horizontally periodic open channel, and the simulations are run at a shear Reynolds number of Reτ = 180. The coupling between the spatially and temporally evolving sediment bed and the flow field is enforced through the explicit immersed boundary method (IBM) of Uhlmann [1]. The flow field is fully resolved and is obtained by integrating the conservation of mass and momentum equations using a pseudo spectral code [2]. On the other hand, the sediment bed is modelled via the Exner equation [3]. Details about the numerical approach are available in [4-5]