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Search Results: 1 - 10 of 3734 matches for " WIM; PARRA "
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Paleolimnological studies of Laguna Chica of San Pedro (VIII Region): Diatoms, hydrocarbons and fatty acid records
URRUTIA,ROBERTO; KOEN,SABBE; CRUCES,FABIOLA; POZO,KARLA; BECERRA,JOSE; ARANEDA,ALBERTO; VYVERMAN,WIM; PARRA,OSCAR;
Revista chilena de historia natural , 2000, DOI: 10.4067/S0716-078X2000000400014
Abstract: diatom, hydrocarbons and fatty acid sedimentary records were used for reconstructing the recent (last 150 years) palaeolimnological history of laguna chica of san pedro (concepción, viii región, chile). cluster analyses (constrained incremental sum of squares) on the diatom data revealed three distinct periods. the first period (1883-1940's) showed a pronounced increase in sedimentation rate and a slight increase in organic matter accumulation. in this period, eutrophic species (aulacoseira granulata and staurosira construens) became increasingly dominant. from the 1940s until the 1970s the diatom signal is more equivocal: after the initial decrease in the relative abundance of a. granulata and s. construens their numbers fluctuate without a clear pattern. sedimentation rates strongly fluctuate in this period. from 1978 onwards eutrophic species are in decline while indicators of oligotrophic conditions, such as cyclotella stelligera and aulacoseira distans, become more abundant. this shift in the lake trophic status could not be attributed to a reduction in the nutrient load from the catchment and we hypothesize that the invasion of the lake by the submersed macrophyte egeria densa has altered nutrient availability to the plankton communities. this is in agreement with the hydrocarbons and fatty acid analyses which demonstrate a shift in carbon number distributions from short chain alkanes and alkanoic acids (typical for microalgae) to long chain molecules (characteristic for higher plants) in the upper layers of the lake sediment
Cognitive assessment in Alzheimer’s disease  [PDF]
Mario A. Parra
Advances in Alzheimer's Disease (AAD) , 2013, DOI: 10.4236/aad.2013.24016
Abstract: Cognitive assessment in Alzheimer’s disease
The Implications of the Sun’s Dragging Effect on Gravitational Experiments  [PDF]
Jose L. Parra
International Journal of Astronomy and Astrophysics (IJAA) , 2017, DOI: 10.4236/ijaa.2017.73014
Abstract: Experimental determinations of Newton’s gravitational constant, Big G, have increased, in number and precision, during the last 30 years. There is, however, a persistent discrepancy between various authors. After examining some literature proposing that the differences in Big G might be a function of the length of the day along the years, this paper proposes an alternative hypothesis in which the periodicity of said variation is a function of the relative periodicity of the Sun-Earth distance. The hypothesis introduced here becomes a direct application of the Kerr Metric that describes a massive rotating star. The Kerr solution for the equations of the General Theory of Relativity of Albert Einstein fits well with this relative periodicity and adequately predicts the arrangement of the ex-perimental G values reported by sixteen different laboratories. Also, the author explains how the Sun disturbs gravity on the surface of the Earth.
Single-Photon Interaction with Beam Splitters  [PDF]
Jose L. Parra
Optics and Photonics Journal (OPJ) , 2018, DOI: 10.4236/opj.2018.82003
Abstract: The production of maxima and minima by the superposition of two or more light signals provides fundamental support for the wave nature of light. This result is based on the study of wave interference phenomena which remains the only approach to explain the production of those maxima and minima. In a system that is prepared to work with only one photon at a time, any detector can signal only one or zero. In 1986, a rigorously controlled experiment was designed by Grangier, G. Roger, and A. Aspect, [Europhys Lett. 1(4), p. 173, 1986] that guaranteed a single-photon beam. The explanation of the experimental results implied the interference of the wave function of a single-photon with itself. Thus, the explanation of interference that is accepted for an ensemble of photons was assumed to be valid for a single photon. In this study, we prepare a Mach-Zehnder interferometer using the same type of beam splitters used by Grangier et al. to test the assumption mentioned above. Our results allow us to explain the results of Grangier et al. because of the interaction between light and the beam splitters. Our results also verify that their wave interpretation of the results is not valid. Here, we present the essential findings of the extensive experimental evidence that supports our ideas.
Corpuscular Point of View to Explain Light’s Properties  [PDF]
Jose L. Parra
Optics and Photonics Journal (OPJ) , 2018, DOI: 10.4236/opj.2018.85013
Abstract: This letter introduces a simple model to explain the Diffraction and Interference of Light. It was created using only a corpuscular point of view. The mean concept of the model introduced in this paper is that light has two independent states of polarization that oscillate with equal frequencies but with a π/2 difference of phase. This model allows the author to determine the intensity of light at any point after it exceeds no edge or any number of them.
Toward a Common Ground for Gravity and Optics  [PDF]
Jose L. Parra
Journal of Applied Mathematics and Physics (JAMP) , 2018, DOI: 10.4236/jamp.2018.69161
Abstract: A long enough period of observation of the Sun’s gravitational dragging effects by using a modified Cavendish’s balance output of experimental evidence shows new patterns. Those patterns can be explained assuming that the Sun has a torus with rotation, precession, and nutation. This purpose of this paper is to introduce the frequencies of all those movements. The torus’s rotational period can be used to explain the Sun’s magnetic pole reversal. Utilizing a modified Cavendish’s balance showed an output of dragging forces stronger than the attraction between the gravitational masses. This tool afforded this research a new experimental possibility to a more precise determination of the Universal Gravitational Constant Big G. Moreover, the dragging forces directly affect any volume of mass, which includes
The Sun and Big G Measurements  [PDF]
Jose L. Parra
Journal of Applied Mathematics and Physics (JAMP) , 2018, DOI: 10.4236/jamp.2018.611202
Abstract: On August 29th, 2018, a scientific team reported a measure of the Universal Gravitational Constant G with the highest precision ever. The team completed three experimental campaigns in the same city over the course of a year. That work provided a complete data set useful analyzing the values of Big G change with the distance to the Sun, as is claimed by the author of this paper.
Climate Change and Industrial Policy
Wim Naudé
Sustainability , 2011, DOI: 10.3390/su3071003
Abstract: Industrial policy (IP) can make an important contribution to both environmental and social sustainability. The purpose of this paper is to explore the new rationale for IP due to climate change and to determine its implications for the how of industrial policy. Five implications are discussed, namely the need for international coordination of IPs; for putting human-development, and not emission targets, as the overriding objective of low-carbon IP; of stimulating innovation for energy efficiency, energy diversification, and carbon capture and storage; and for aligning IP with trade policies. Finally the funding needs of low-carbon IPs are discussed, and the importance of private sector funding emphasized.
Lessons from animal models of arthritis over the past decade
Wim Berg
Arthritis Research & Therapy , 2009, DOI: 10.1186/ar2803
Abstract: Animal models have contributed to the understanding of basic mechanisms of joint disease. There is marked diversity among the numerous models, and arthritis has been induced by various stimuli. These include the generation of auto-immunity to cartilage components, nonspecific skewing of autoimmunity with adjuvants, and triggering with exogenous agents such as bacteria and viruses. More recently, focused transgenic manipulation has added novel variants (Table 1).The wide variety of agents that can induce experimental arthritis with histopathological features close to those of human arthritides suggests that disparate etiological pathways may exist in rheumatoid arthritis (RA). No single animal model of arthritis truly represents the human disease, but the models mimic various aspects and can be used as tools to understand particular pathways.Developments over the past decade include the generation of novel models as well as pathway analysis and therapeutic targeting in classic models. Aspects peculiar to individual models are of value but must be interpreted with caution. Much can be learned from the general validity of mediator involvement and other common concepts. This review will not discuss the developments in immune regulation and the use of models to identify disease susceptibility genes, but will focus on insights into cytokine involvement and aspects of joint destruction. The process of cartilage erosion remains hard to evaluate in patients. Synovial biopsies are now performed in many early arthritis clinics, but samples of damaged bone and cartilage become available only late in the disease, after joint replacement. Models therefore provide valuable tools.Characteristic histopathological features of RA include immune complexes (ICs) in the articular cartilage layers and variable amounts of macrophages, T cells and plasma cells in the synovium, often accompanied by fibrosis and synovial hyperplasia. Formation of autoantibodies, including rheumatoid factor an
Waarom schrijft u? Waarom schrijft u in het Nederlands? Literatuur en taal in de Nederlandse Antillen en Aruba
Wim Rutgers
Tydskrif vir letterkunde , 2004,
Abstract: Language and literature in the Netherlands Antilles and Aruba [Dutch] Four languages are used daily on the six islands that encompass the Netherlands Antilles and Aruba and form part of the Kingdom of the Netherlands: the national languages English and Papiamento (an interlanguage based upon Dutch, English, Portuguese and Spanish), the Dutch of the Kingdom and the regional language, Spanish. Each of these four languages has a literary tradition on the islands. Although Dutch is still the official language and used as the language of school instruction and the written language of business its wider functions have diminished. Over the past decades the language has virtually disappeared from the islands' cultural life, with the consequence that Dutch-Antillean literature is also gradually declining. On Cura ao, Aruba and Bonaire Papiamento predominates and will have to replace Dutch as the literary language, but as long as it is not a language of instruction this will be problematic. Over the last couple of years an important literary tradition in English has developed on Saint Maartin, Saba and Saint-Eustatius. Alongside the written literature an oral tradition exists up to the present day on the islands. Cola Debrot, Boeli van Leeuwen, Tip Marugg and Frank Martinus Arion are well known internationally but there are many other writers who belong to the literary canons of the islands. Key Words: Netherlands Antilles, Aruba, Papiamento, Antillean literature. Talen en literatuur in de Nederlandse Antillen en Aruba Op de zes eilanden die samen als de Nederlandse Antillen en Aruba deel zijn van het Koninkrijk der Nederlanden worden dagelijks vier talen gebruikt: de nationale talen Papiamentu en Engels, het Nederlands van het Koninkrijk en het Spaans van de regio. Elk van deze vier talen heeft een literaire traditie op de eilanden. Het Nederlands heeft in de loop van de tijd steeds minder functies gekregen maar is nog steeds offici le taal, schooltaal en schriftelijke bestuurstaal. Uit het culturele leven is de taal de laatste decennia nagenoeg verdwenen, wat inhoudt dat ook de Nederlands-Antilliaanse literatuur langzamerhand lijkt te verdwijnen. Op Cura ao, Aruba en Bonaire zal het Papiamentu de functie van literaire taal moeten gaan overnemen, maar dat is nog problematisch zolang deze taal niet de instructietaal van het onderwijs wordt. Op Sint-Maarten, Saba en Sint-Eustatius ontwikkelt zich de laatste jaren een belangwekkende literatuur in het Engels. Naast de geschreven literatuur kennen de eilanden een orale traditie die voortduurt tot vandaag de dag. De in het buitenland bekendste schrijvers zijn Cola Debrot, Boeli van Leeuwen, Tip Marugg en Frank Martinus Arion, maar er zijn talrijke andere schrijvers die tot de eilandelijke canons behoren. Trefwoorden: Nederlandse Antillen, Aruba, Papiamentu, Antilleaanse literatuur. Tydskrif vir letterkunde Vol.41(1) 2004: 115-129
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