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Search Results: 1 - 10 of 39918 matches for " Irene Alvarado-Van der Laat "
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Tortuguero National Park, Costa Rica: Baseline CO2 Emissions from Boat Tours into the Channels System  [PDF]
Irene Alvarado-Van der Laat
Low Carbon Economy (LCE) , 2014, DOI: 10.4236/lce.2014.51003
Abstract:

Tortuguero National Park located on the Caribbean coast of Costa Rica is only accessible by boat or air and attracts an average of 130,000 visitors yearly. The main activity of the park is the turtle nesting and hatching along the beaches as well as the observation of wildlife in the channel sys- tem. This makes it important to study the CO2 emitted by the tours operating in the park. To cal- culate these emissions researchers gathered data on engine type, horsepower and duration of idle while boats waited to buy tickets at the park entrance. The study found that tour operators emit- ted a minimum of 5.5 tons of CO2 per year into the atmosphere and water. It is likely that the park is more polluted than immediately evident.

Ecotourism, Stated Preferences, a Paradox between Environmental Awareness and Environmental Actions: The Case of Monteverde, Costa Rica  [PDF]
Irene Alvarado-Van der Laat
Low Carbon Economy (LCE) , 2015, DOI: 10.4236/lce.2015.64011
Abstract: This study aims to assess the relation between the so called “Ecotourism” behavior and Willingness-To-Pay (WTP) in order to compensate on site for their carbon foot print, plus their familiarity with common environmental terms, in the Monteverde Region of Costa Rica. A Contingent Valuation Method (CVM) was decided upon as the best way to determine the willingness to pay (WTP). While the scope of this study is limited by the low season for tourism, the study finds a paradox between the behaviors of the self-called ecotourist suggesting that the term is more related to the location of the area visited, rather than any attempt by the tourist to alter their travel behavior. That could have a negative impact on the very wildlife where the park is trying to protect.
Importancia de inculcar valores en menores de edad como prevención de la violencia
Alpízar Alvarado,Daniela; Calvo Fonseca,Sebastián; Garita Campos,Mauricio; Méndez Mora,Sergio; Mora López,Allan; Loría Garita,Diana; Van der Laat Villalobos,Sylvia; Varela Calderón,Tracy; Flores Sandí,Grettchen;
Medicina Legal de Costa Rica , 2011,
Abstract: this work was done with children and adolescents of a leadership childhood program. its objective was to teach those kids the importance of values, such as: tolerance, teamwork, friendship, respect, generosity, honesty, solidarity, perseverance, kindness, among others; as a form to prevent violent acts. based on data collected through surveys, it was found that there were important lack sin terms of the values perception. and it also showed the importance, of the promotion of didactic and entertaining teaching, in order to achieve instill education and that this succeed to reach the mind of each child.
Evaluation of tropospheric ozone columns derived from assimilated GOME ozone profile observations
A. T. J. de Laat,R. J. van der A,M. van Weele
Atmospheric Chemistry and Physics Discussions , 2009,
Abstract: Tropospheric O3 column estimates are produced and evaluated from spaceborne O3 observations by the subtraction of assimilated O3 profile observations from total column observations, the so-called Tropospheric O3 ReAnalysis or TORA method. Here we apply the TORA method to six years (1996–2001) of ERS-2 GOME/TOMS total O3 and ERS-2 GOME O3 profile observations using the TM5 global chemistry-transport model with a linearized O3 photochemistry parameterization scheme. Free running TM5 simulations show good agreement with O3 sonde observations in the upper-tropospheric and lower stratospheric (UTLS). Assimilation of GOME O3 profile observations improves the comparisons in the tropical UTLS region but slightly degrades the model-to-sonde comparisons in the extra-tropical UTLS for both short day-do-day variability as well as for monthly means. We suggest that this degradation is related to the large ground pixel size of the GOME O3 measurements (960×100 km) in combination with retrieval and calibration errors. The assimilation of GOME O3 profile observations does counter the gradual multiyear mid-latitude stratospheric O3 accumulation caused by the overstrong stratospheric meridional circulation in TM5. The evaluation of daily and monthly tropospheric O3 columns obtained from total column observations and using the TORA methodology shows realistic residuals within the tropics but unrealistically large deviations outside of the tropics, although average biases remain small for the monthly means. The findings of this paper suggest that improvements can be expected by using O3 observations from present-day instruments like MetOp/GOME-2 and EOS-AURA/OMI.
Evaluation of tropospheric ozone columns derived from assimilated GOME ozone profile observations
A. T. J. de Laat,R. J. van der A,M. van Weele
Atmospheric Chemistry and Physics (ACP) & Discussions (ACPD) , 2009,
Abstract: Tropospheric O3 column estimates are produced and evaluated from spaceborne O3 observations by the subtraction of assimilated O3 profile observations from total column observations, the so-called Tropospheric O3 ReAnalysis or TORA method. Here we apply the TORA method to six years (1996–2001) of ERS-2 GOME/TOMS total O3 and ERS-2 GOME O3 profile observations using the TM5 global chemistry-transport model with a linearized O3 photochemistry parameterization scheme. Free running TM5 simulations show good agreement with O3 sonde observations in the upper-tropospheric and lower stratospheric region (UTLS), both for short day-to-day variability as well as for monthly means. The assimilation of GOME O3 profile observations counteracts the mid-latitude stratospheric O3 drift caused by the overstrong stratospheric meridional circulation in TM5. Assimilation of GOME O3 profile observations also improves the bias and correlations in the tropical UTLS region but slightly degrades the model-to-sonde correlations and bias of extra-tropical UTLS. We suggest that this degradation is related to the large ground pixel size of the GOME O3 measurements (960×100 km) in combination with retrieval and calibration errors. The added value of the assimilation of GOME O3 profiles compared to stand-alone model simulations lays in the long term variations of stratospheric O3, not in short term synoptic variations. The evaluation of daily and monthly tropospheric O3 columns obtained from total column observations and using the TORA methodology shows that the use of GOME UV-VIS nadir O3 profiles in combination with the spatial resolution of the model does not result in satisfactory residual tropospheric ozone columns.
Trends in Computer Network Modeling Towards the Future Internet
Jeroen van der Ham,Mattijs Ghijsen,Paola Grosso,Cees de Laat
Computer Science , 2014,
Abstract: This article provides a taxonomy of current and past network modeling efforts. In all these efforts over the last few years we see a trend towards not only describing the network, but connected devices as well. This is especially current given the many Future Internet projects, which are combining different models, and resources in order to provide complete virtual infrastructures to users. An important mechanism for managing complexity is the creation of an abstract model, a step which has been undertaken in computer networks too. The fact that more and more devices are network capable, coupled with increasing popularity of the Internet, has made computer networks an important focus area for modeling. The large number of connected devices creates an increasing complexity which must be harnessed to keep the networks functioning. Over the years many different models for computer networks have been proposed, and used for different purposes. While for some time the community has moved away from the need of full topology exchange, this requirement resurfaced for optical networks. Subsequently, research on topology descriptions has seen a rise in the last few years. Many different models have been created and published, yet there is no publication that shows an overview of the different approaches.
The role of renin angiotensin system inhibition in kidney repair
Irene M van der Meer, Paolo Cravedi, Giuseppe Remuzzi
Fibrogenesis & Tissue Repair , 2010, DOI: 10.1186/1755-1536-3-7
Abstract: Chronic kidney disease (CKD) represents a major health problem worldwide. It has been estimated that approximately 830,000 deaths every year are linked to renal diseases, but the scale of the problem is probably largely underestimated [1] Costs for renal replacement therapies cannot be afforded on a population basis by most developing countries, and estimates predict that economic expenses for these treatments are becoming very problematic for wealthier nations too. Therefore, identifying mechanisms that sustain renal disease progression and those that allow recovery of renal function and structural integrity after injury will be crucial to develop hypothesis-driven therapies able to promote remission or even regression of CKD. This will be of even higher importance for global morbidity and mortality because renal impairment also represents a major risk factor for cardiovascular disease [1].Independently from the initial insult, chronic nephropathies seem to share common pathogenic mechanisms leading to progressive renal function loss and fibrosis [2]. Targeting blood pressure (BP) and proteinuria can reduce the rate of kidney function decline and prevent or delay the need for renal replacement therapy in many patients. The cornerstone of current treatment is inhibition of the renin angiotensin system (RAS), which has been consistently described to improve renal function with concomitant regression of kidney structural changes in animal models. Similar effects have been reported in selected patients, providing evidence that the kidney has some regenerative capacity that might be boosted by specific and targeted treatment [3,4]. In this paper, we first review the evidence both from experimental studies and from clinical studies in humans that RAS inhibition can induce renal structural and functional changes. We then provide an extensive summary of the possible direct or indirect mechanisms by which inhibition of the RAS contributes to kidney repair.Experimental and c
New insights in understanding the pathogenesis of spondyloarthropathies
Irene van der Horst-Bruinsma, J Bart A Crusius
Arthritis Research & Therapy , 2010, DOI: 10.1186/ar2895
Abstract: Gene expression profiles may clarify our understanding of the pathophysiology of disease, and by redefining pathways of inflammation may offer new alternatives for treatment of chronic diseases such as the spondyloarthropathies (SpA). If the expression profiles are specific for the disease or for a particular subgroup of patients, the data may generate biomarkers to classify the disease and define the stage of the inflammatory process. Genome-wide RNA expression analysis will thus lead to new insights in the pathogenesis of heterogeneous diseases such as SpA. These studies are expensive and powerful statistical approaches are necessary for achieving reproducible results. The potential gains, however, are of great clinical importance. Attention should be given to the selection of patients, to the state of the inflammatory process and to the possible effect of current therapy in the enhancing or silencing of this process.As far as we know, only two studies have used whole genome expression profiles in blood from SpA patients and controls. Both studies follow a similar protocol; the study published in the previous issue of Arthritis Research and Therapy used an Affymetrix microarray system [1], and an Australian study published online in Annals of the Rheumatic Diseases used an Illumina Chip [2]. Both studies use a primary set and a validation set. Both studies also use peripheral blood, and obviously the pathogenesis of joints may be slightly different when the organ of disease is targeted. The approach, however, is valid.The study described by Sharma and colleagues showed several interesting associations of axial SpA with the innate immune system - like the NOD-like receptor family member inflammasome component NLRP2, secre tory leukocyte peptidase inhibitor I, and secreted protein acidic, cysteine-rich (also known as osteonectin) - and with inflammation markers (IL-1 receptors) and markers of bone remodeling (Kringle containing transmembrane protein 1 (KREMEN1)) [1]
Ruled quartic surfaces, models and classification
Irene Polo-Blanco,Marius van der Put,Jaap Top
Mathematics , 2009,
Abstract: New historical aspects of the classification, by Cayley and Cremona, of ruled quartic surfaces and the relation to string models and plaster models are presented. In a `modern' treatment of the classification of ruled quartic surfaces the classical one is corrected and completed. A conceptual proof is presented of a result of Rohn concerning curves in $\mathbb{P}^1\times \mathbb{P}^1$ of bi-degree $(2,2)$. The string models of Series XIII (of some ruled quartic surfaces) are based on Rohn's result.
SCIAMACHY CO over land and oceans: 2003–2007 interannual variability
A. M. S. Gloudemans, A. T. J. de Laat, H. Schrijver, I. Aben, J. F. Meirink,G. R. van der Werf
Atmospheric Chemistry and Physics (ACP) & Discussions (ACPD) , 2009,
Abstract: We present a new method to obtain accurate SCIAMACHY CO columns over clouded ocean scenes. Based on an improved version of the Iterative Maximum Likelihood Method (IMLM) retrieval algorithm, we now have retrieved five years of data over both land and clouded ocean scenes between 2003 and 2007. The ocean-cloud method uses the CH4 columns retrieved simultaneously with the CO columns to determine the cloud top height. The CH4 cloud top height is in good agreement with the FRESCO+ cloud top height determined from UV-VIS oxygen-A band measurements, providing confidence that the CH4 cloud top height is a good diagnostic of the cloud top height over (partially) clouded ocean scenes. The CO measurements over clouded ocean scenes have been compared with collocated modeled CO columns over the same clouds and agree well. Using clouded ocean scenes quadruples the number of useful CO measurements compared to land-only measurements. The five-year CO data set over land and clouded ocean scenes presented here is based on an improved version of the IMLM algorithm which includes a more accurate determination of the random instrument-noise error for CO. This leads to a smaller spread in the differences between single CO measurements and the corresponding model values. The new version, IMLM version 7.4, also uses updated spectroscopic parameters for H2O and CH4 but this has only a minor impact on the retrieved CO columns. The five-year data set shows significant interannual variability over land and over clouded ocean scenes. Three examples are highlighted: the Asian outflow of pollution over the northern Pacific, the biomass-burning outflow over the Indian Ocean originating from Indonesia, and biomass burning in Brazil. In general there is good agreement between observed and modeled seasonal cycles and interannual variability.
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