THE INFLUENCE OF THE 1992-1993 EL NINO ON THE REPRODUCTIVE BIOLOGY OF Scomber japonicus peruanus (JORDAN & HUBB, 1925)

The influence of the 1992-1993 El Nino events on the reproductive behavior of the Scomber japonicus peruanus (Chub mackerel) was studied from samples collected monthly, along the Peruvian coast (3 degrees 23`S-14 degrees 00`S), from January 1990 to December 1993. The monthly variation of the gonadosomatic index and the frequency of the periods of gonad maturation evidenced that the spawning of the species occurred all year long, being more intense in summer. The values of the gonadosomatic index were higher during the occurrence of the 1992-1993 El Nino, while the body weight and gonad weight decreased. Regarding the condition factor, its values decreased in females over 35 cm in fork length.

Growth parameters and mortality rate of the Scomber japonicus peruanus (Jordan & Hubb, 1925) along the Peruvian coast, South Pacific

The growth parameters and the mortality rates of the Scomber japonicus peruanus (Chub mackerel) were studied based on monthly data of frequency of fork length classes obtained from commercial landings off the Peruvian coast from 1996 to 1998. The asymptotic body length and growth rate values obtained by the ELEFAN I (Electronic Length Frequency Analysis) ranged from 40.20 cm to 42.20 cm and from 0.38 to 0.39, respectively. The oscillation amplitude was 0.60; the Winter point values varied from 0.50 to 0.60 and the performance index from 2.79 to 2.84. The total mortality rate of the Chub mackerel obtained by the linearized catch curve oscillated between 1.68 and 3.35. The rate of fishing mortality varied from 1.16 to 2.78 and the exploitation rate from 0.68 to 0.84. The annual rate of natural mortality estimated by the Pauly`s method ranged from 0.52 to 0.53. The results obtained allow us to conclude that the longevity of the Chub mackerel was slightly over seven years.

Invasion of the dinoflagellate Ceratium furcoides (Levander) Langhans 1925 at tropical reservoir and its relation to environmental variables

Dinoflagellates of the genus Ceratium are chiefly marine but there are rare occurrences in freshwater. In this study we analyze the invasion and progressive establishment of Ceratium furcoides, an exotic species, in the Furnas Reservoir. Samples were taken at 36 points in the reservoir, during the months of March, June, September and December, 2007. Measurements of some physical and chemical variables were simultaneously performed at each site. The occurrence of C. furcoides was registered at 20 sites, with densities varying between 0.57 and 28,564,913.0 ind.m(-3). Blooms of this species were recorded in points which were classified as mesotrophic, coinciding with the places receiving high amounts of untreated domestic sewage. C. furcoides density was correlated with temperature, nutrients (nitrate and nitrite) and water electric conductivity. The highest density was recorded in June when temperature was low. The presence of Ceratium furcoides in the reservoir apparently has not yet affected the reservoir water quality or other plankton communities. However, if it becomes fully established it could perhaps become a problem in the reservoir or even to spread out to other reservoirs in Rio Grande basin.

A simple and precise conductometric method for the determination of losartan in pharmaceutical products

Losartan is an antihypertensive agent that lost its patent protection in 2010, and, consequently, it has been available in generic form. The latter motivated the search for a rapid and precise alternative method. Here, a simple conductometric titration in aqueous medium is described for the losartan analysis in pharmaceutical formulations. The first step of the titration occurs with the protonation of losartan producing a white precipitate and resulting in a slow increase in conductivity. When the protonation stage is complete, a sharp increase in conductivity occurs which was determined to be due to the presence of excess of acid. The titrimetric method was applied to the determination of losartan in pharmaceutical products and the results are comparable with values obtained using a chromatographic method recommended by the United States Pharmacopoeia. The relative standard deviation for successive measurements of a 125 mg L-1 (2.71x10(-4) mol L-1) losartan solution was approximately 2%. Recovery study in tablet samples ranged between 99 and 102.4%. The procedure is fast, simple, and represents an attractive alternative for losartan quantification in routine analysis. In addition, it avoids organic solvents, minimizes the risk of exposure to the operator, and the waste treatment is easier compared to classical chromatographic methods.

Underlying Event measurements in pp collisions at root s=0.9 and 7 TeV with the ALICE experiment at the LHC

We present measurements of Underlying Event observables in pp collisions at root s = 0 : 9 and 7 TeV. The analysis is performed as a function of the highest charged-particle transverse momentum p(T),L-T in the event. Different regions are defined with respect to the azimuthal direction of the leading (highest transverse momentum) track: Toward, Transverse and Away. The Toward and Away regions collect the fragmentation products of the hardest partonic interaction. The Transverse region is expected to be most sensitive to the Underlying Event activity. The study is performed with charged particles above three different p(T) thresholds: 0.15, 0.5 and 1.0 GeV/c. In the Transverse region we observe an increase in the multiplicity of a factor 2-3 between the lower and higher collision energies, depending on the track p(T) threshold considered. Data are compared to PYTHIA 6.4, PYTHIA 8.1 and PHOJET. On average, all models considered underestimate the multiplicity and summed p(T) in the Transverse region by about 10-30%.

Measurement of prompt J/psi and beauty hadron production cross sections at mid-rapidity in pp collisions at root s=7 TeV

The ALICE experiment at the LHC has studied J/psi production at mid-rapidity in pp collisions at root s = 7 TeV through its electron pair decay on a data sample corresponding to an integrated luminosity L-int = 5.6 nb(-1). The fraction of J/psi from the decay of long-lived beauty hadrons was determined for J/psi candidates with transverse momentum p(t) > 1,3 GeV/c and rapidity vertical bar y vertical bar < 0.9. The cross section for prompt J/psi mesons, i.e. directly produced J/psi and prompt decays of heavier charmonium states such as the psi(2S) and chi(c) resonances, is sigma(prompt J/psi) (p(t) > 1.3 GeV/c, vertical bar y vertical bar < 0.9) = 8.3 +/- 0.8(stat.) +/- 1.1 (syst.)(-1.4)(+1.5) (syst. pol.) mu b. The cross section for the production of b-hadrons decaying to J/psi with p(t) > 1.3 GeV/c and vertical bar y vertical bar < 0.9 is a sigma(J/psi <- hB) (p(t) > 1.3 GeV/c, vertical bar y vertical bar < 0.9) = 1.46 +/- 0.38 (stat.)(-0.32)(+0.26) (syst.) mu b. The results are compared to QCD model predictions. The shape of the p(t) and y distributions of b-quarks predicted by perturbative QCD model calculations are used to extrapolate the measured cross section to derive the b (b) over bar pair total cross section and d sigma/dy at mid-rapidity.

Wecken type problems for self-maps of the Klein bottle

We consider various problems regarding roots and coincidence points for maps into the Klein bottle . The root problem where the target is and the domain is a compact surface with non-positive Euler characteristic is studied. Results similar to those when the target is the torus are obtained. The Wecken property for coincidences from to is established, and we also obtain the following 1-parameter result. Families which are coincidence free but any homotopy between and , , creates a coincidence with . This is done for any pair of maps such that the Nielsen coincidence number is zero. Finally, we exhibit one such family where is the constant map and if we allow for homotopies of , then we can find a coincidence free pair of homotopies.

Invasion of the dinoflagellate Ceratium furcoides (Levander) Langhans 1925 at tropical reservoir and its relation to environmental variables

Dinoflagellates of the genus Ceratium are chiefly marine but there are rare occurrences in freshwater. In this study we analyze the invasion and progressive establishment of Ceratium furcoides, an exotic species, in the Furnas Reservoir. Samples were taken at 36 points in the reservoir, during the months of March, June, September and December, 2007. Measurements of some physical and chemical variables were simultaneously performed at each site. The occurrence of C. furcoides was registered at 20 sites, with densities varying between 0.57 and 28,564,913.0 ind.m-3. Blooms of this species were recorded in points which were classified as mesotrophic, coinciding with the places receiving high amounts of untreated domestic sewage. C. furcoides density was correlated with temperature, nutrients (nitrate and nitrite) and water electric conductivity. The highest density was recorded in June when temperature was low. The presence of Ceratium furcoides in the reservoir apparently has not yet affected the reservoir water quality or other plankton communities. However, if it becomes fully established it could perhaps become a problem in the reservoir or even to spread out to other reservoirs in Rio Grande basin.

Cognición, lengua y dinámicas biopoéticas de evolución social en Ortega y Gasset: modelos cognitivos de organización temporal del concepto humano en el texto "La deshumanización del arte" (1925)

Directora: Juana Teresa Guerra de la Torre. Programa de doctorado: Nuevas perspectivas cognitivas en los estudios de lengua, literatura y traducción

Auswirkungen des Klimawandels auf die klein- und großräumige genetische Populationsstruktur von Makrozoobenthos in Rhein, Main und Mosel

In den letzten Jahrzehnten wurde eine deutliche, anhaltende Veränderung des globalen Klimas beobachtet, die in Zukunft zu einer Erhöhung der durchschnittlichen Oberflächentemperatur, erhöhten Niederschlagsmengen und anderen gravierenden Umweltveränderungen führen wird (IPCC 2001). Der Klimawandel wird in Flüssen sowohl mehr Extremereignisse verursachen als auch das Abflussregime bisher schmelzwasserdominierter Flüsse zu grundwassergespeisten hin ändern; dies gilt insbesondere für den Rhein (MIDDELKOOP et al. 2001). Um die möglichen Auswirkungen dieser Veränderungen auf die genetische Populationsstruktur von Makrozoobenthosorganismen vorhersagen zu können, wurden in den grundwassergespeisten Flüssen Main und Mosel sowie im Rhein Entnahmestellen oberhalb und unterhalb von Staustufen beprobt, die durch kontrastierende Strömungsverhältnisse als Modell für die zu erwartenden Änderungen dienten. Als Untersuchungsobjekt wurden Dreissena polymorpha PALLAS 1771 sowie Dikerogammarus villosus SOWINSKI 1894 herangezogen. Sie zeichnen sich durch hohe Abundanzen aus, sind aber unterschiedlich u.a. hinsichtlich ihrer Besiedlungsstrategie und –historie. Bei beiden Spezies sind die phylogeographischen Hintergründe bekannt; daher wurde auch versucht, die Einwanderungsrouten in der Populationsstruktur nachzuweisen (phylogeographisches Szenario). Dies konkurrierte mit der möglichen Anpassung der Spezies an das Abflussregime des jeweiligen Flusses (Adaptations-Szenario). Die Populationen wurden molekulargenetisch mit Hilfe der AFLP-Methode („Amplified-Fragment Length Polymorphism“) untersucht. Die Ergebnisse zeigen, dass D. polymorpha deutlich durch die Abflussregimes der Flüsse (Schmelz- oder Grundwasserdominanz) beeinflusst wird. Die Allelfrequenzen in Populationen des Rheins sind von denen der beiden grundwassergespeisten Flüsse Main und Mosel deutlich unterscheidbar (Adaptations-Szenario). Jedoch ist kein Unterschied der genetischen Diversitäten zu beobachten; das ist auf die lange Adaptation an ihre jeweiligen Habitate durch die lange Besiedlungsdauer zurückzuführen. Dies ist auch der Grund, warum die Einwanderungsrouten anhand der Populationsstruktur nicht mehr nachzuweisen waren. Die kontrastierenden Strömungsverhältnisse um die Staustufen hatten ebenfalls keine konsistenten Auswirkungen auf die genetische Diversität der Populationen. Diese Ergebnisse zeigen eine hohe phänotypische Plastizität der Spezies und dadurch eine große Anpassungsfähigkeit an wechselnde Umweltbedingungen, die unter anderem für den großen Erfolg dieser Spezies verantwortlich ist. D. villosus wanderte erst vor Kurzem in das Untersuchungsgebiet ein; die Einwanderungsroute war anhand der genetischen Diversität nachvollziehbar (phylogeographisches Szenario); durch die kurze Besiedlungsdauer war eine Adaptation an die divergenten Abflussregime der Flüsse nicht zu erwarten und wurde auch nicht gefunden. Dagegen war ein deutlicher negativer Einfluss von starker Strömung auf die genetische Diversität nachweisbar. Die Ergebnisse weisen darauf hin, dass die zukünftigen Auswirkungen des Klimawandels auf die Strömungsgeschwindigkeit negative Konsequenzen auf die genetische Diversität von D. villosus haben werden, während D. polymorpha hier keine Auswirkungen erkennen lässt. Die Auswirkungen des veränderten Abflussregimes im Rhein sind für D. villosus mit den vorliegenden Daten aufgrund der kurzen Besiedlungsdauer nicht vorhersagbar; D. polymorpha wird durch die Veränderung des Rheins zu einem grundwassergespeisten Fluss zwar einen Wandel in der genetischen Struktur erfahren, aber auch hier keine Einbußen in der genetischen Diversität erleiden.

Dispersive wave solutions of the klein-gordon equation in cosmology

L'equazione di Klein-Gordon descrive una ampia varietà di fenomeni fisici come la propagazione delle onde in Meccanica dei Continui ed il comportamento delle particelle spinless in Meccanica Quantistica Relativistica. Recentemente, la forma dissipativa di questa equazione si è rivelata essere una legge di evoluzione fondamentale in alcuni modelli cosmologici, in particolare nell'ambito dei cosiddetti modelli di k-inflazione in presenza di campi tachionici. L'obiettivo di questo lavoro consiste nell'analizzare gli effetti del parametro dissipativo sulla dispersione nelle soluzioni dell'equazione d'onda. Saranno inoltre studiati alcuni tipici problemi al contorno di particolare interesse cosmologico per mezzo di grafici corrispondenti alle soluzioni fondamentali (Funzioni di Green).