Thesis (Ph. D.)--University of Hawaii at Manoa, 2002. / Includes bibliographical references (leaves 62-66).

The Bouguer correction using a mean sea level reduction datum compensates the gravitational effect of the mass of the terrain above sea level. This correction generally results in long -wavelength Bouguer gravity anomalies if the mass of the terrain is isostatically compensated. These anomalies correlate with regional elevations, especially in areas with significant regional variations in elevation, such as western North America. The adverse effect of this correlation is that other anomalies of potential interest in a tectonic or geologic analysis may be overshadowed. To circumvent this problem in an analysis of gravity in Arizona, a residual Bouguer gravity anomaly map has been constructed for the state in which a trend surface of the elevation is used as the reduction datum in the Bouguer correction. Elevation values from topographic maps and not gravity station elevations have been used to prepare the regional elevation datum because station elevations do not adequately sample the range in elevations. Small- and large-wavelength residual Bouguer gravity anomalies and trends of anomalies are brought out more clearly by the residual Bouguer gravity anomaly map than by previous gravity maps. The most prominent features in the residual anomalies are a strong gravity gradient 50 km wide striking west -northwest across southern Arizona and a large wavelength residual Bouguer gravity anomaly low in the Coconino Plateau of northwest Arizona . The long-wavelength residual Bouguer gravity anomalies reflect lateral density variations in the crust and mantle that may be related to lateral temperature variations.

No description available.

No description available.

Iceland has long been thought to be underlain by a thermal upwelling, or plume, rising from deep within the mantle. This study tests this hypothesis, by a) seeking evidence for a plume in the lower mantle in azimuth anomalies at the NORSAR array and b) mapping the three-dimensional structure of the mantle beneath Iceland using teleseismic tomography and data from an Iceland-wide broadband seismometer network. A temporary network of 30 digital broadband, three-component seismographs was deployed 1996-1998 to complement the existing, permanent seismic network on Iceland. This created a dense, well-distributed network. 3159 P-wave and 1338 S-wave arrival times were measured and inverted for velocity structure using the ACH method of teleseismic tomography. The preferred models are well-resolved down to -400 km, and reveal a low-velocity body with anomaly up to -2.9% in V(_p)) and -4.9% in V(_s) beneath central Iceland. This persists throughout the entire model depth range. The amplitudes of the anomalies imply an excess temperature of 200-300 K relative to the surrounding mantle. The morphology of the anomaly changes from cylindrical to tabular at 250-300 km depth, a feature that resolution tests suggest is real. This is consistent with the predictions of some convection models and suggests that the plume is restricted to the upper mantle. Anomalies in v(_p) and v(_s) provide evidence for lateral flow of material beneath the Reykjanes Ridge to the southeast in the depth range 50-200 km. Similar anomalies are present beneath the Kolbeinsey Ridge to the north only beneath 160 km. This shows that flow outwards beneath the Kolbeinsey Ridge is blocked by the Tjörnes Fracture Zone above 160 km. Azimuthal anomalies detected on the NORSAR array for rays travelling beneath Iceland at 1,500 km depth are consistent with a plume beneath Iceland at this lower-mantle depth with a Gaussian radius of 125 km and a strength of 1.5%. The observations do not serve as proof for such an anomaly because the solution is not unique. V(_p)/V(_s) ratios are 1% high throughout most of the plume, and up to 3.2% high at depths of 100-300 km beneath central and east-central Iceland. This suggests that up to a few percent of melt pervades the entire plume.

No description available.

Les tècniques d'hibridació in situ fluorescent aplicades sobre nuclis d'espermatozoides humans prèviament descondensats permeten la seva caracterització citogenètica i, en conseqüència, determinar el risc de transmissió d'una anomalia cromosòmica a la descendència.Hem aplicat aquesta metodologia en espermatozoides procedents d'individus control, per tal de determinar la incidència basal d'anomalies en la població general, així com en individus que per les seves particularitats, sospitem que poden presentar una incidència d'anomalies cromosòmiques superior a la població control.L'anàlisi dels resultats ha posat de manifest que els mecanismes que originen gàmetes amb aneuploïdies afecten preferentment a alguns cromosomes, concretament el cromosoma 21 i els cromosomes sexuals.Els pares d'individus amb la síndrome de Down d'origen patern presenten un increment significatiu d'aneuploïdies pel cromosoma 21.En individus portadors d'anomalies cromosòmiques estructurals, la proporció dels genotips resultants de cada tipus de segregació no s'ajusta a la proporció 1:1 esperada, suggerint l'existència de punts de control al llarg de la meiosi que eliminen selectivament cèl·lules germinals en funció del seu contingut cromosòmic. Per algunes reorganitzacions, el risc de transmissió d'una anomalia cromosòmica a la descendència es pot veure incrementat per la presència d'efectes intercromosòmics.En individus amb la síndrome de Klinefelter, els nostres resultats confirmen la incapacitat de la línia cel·lular 47,XXY d'iniciar la meiosi. L'increment d'espermatozoides portadors d'anomalies numèriques pels cromosomes sexuals es podria explicar pel desenvolupament de la meiosi en un ambient testicular anormal, conduint a un increment de segregacions errònies de les cèl·lules diploides 46,XY presents al teixit testicular.En individus amb cariotip 47,XYY, algunes cèl·lules amb aquesta dotació cromosòmica tenen la capacitat d'iniciar la meiosi. Les dades en aquests individus suggereixen l'existència d'un bloqueig de les cèl·lules aneuploides en l'estadi d'espermatòcit primari, secundari o en l'estadi d'espermàtide, donant lloc a una eliminació continuada de les cèl·lules anormals al llarg de l'espermatogènesi.Les avantatges que presenten les tècniques d'hibridació in situ fluorescent per a l'estudi citogenètic de l'espermatozoide humà ha permès la seva incorporació com a eina de diagnòstic genètic en individus de risc. Tenint en compte que la majoria d'aquests individus presenten problemes de fertilitat, l'anàlisi del contingut cromosòmic dels espermatozoides permet determinar, per a cada cas en particular, el risc potencial de transmissió a la descendència. Aquesta informació pot ser utilitzada per establir el programa de reproducció assistida més adequat a les característiques de cada cas. / Fluorescent in situ hybridization methodology allows analyzing the chromosome content of spermatozoa. With the analysis of the gametes, it is possible to determine the real risk of transmission of a chromosome abnormality to the offspring.We have used this methodology in the cytogenetic study of human spermatozoa obtained from two types of men; control men, in order to determine the basal incidence of chromosome anomalies in the normal population, and high risk men, that is, patients that for different reasons, we suspect the presence of a increased incidence of chromosome anomalies.Our results underline that the biological mechanisms which are behind of the non-disjunction phenomenon affected much more some chromosomes than others.The fathers of Down syndrome children of paternal origin showed a significant increased of 21 aneuploidies, suggesting that these patients had an increase risk of transmission of a chromosomal abnormality to the offspring.In carriers of structural reorganizations, the proportion of the expected genotypes in each type of segregation differs of the 1:1 proportion. This result suggests the presence of meiotic checkpoint along meiosis eliminating selectively those cells with chromosome anomalies. In some types of reorganizations, the risk of transmission to the offspring could also be increased for the presence of interchromosomal effects.In Klinefelter patients, our results underline the inability of the 47,XXY cell line to initiate the meiotic process. The abnormal sex chromosome constitution found in spermatozoa could be attributed to segregation errors in XY cells placed in a compromised testicular environment.In 47,XYY patients, although some aneuploid cells are meiotically competent, it seems that there is a continuous elimination of chromosomal abnormal germ cells along spermatogenesis, parallel to an increase in the percentage of normal cells.Altogether, the data underline the importance of incorporating the screening of aneuploidies in sperm in the genetic screening of affected patients, in order to determine the real risk of transmission of a numerical chromosome abnormality to the offspring.Obviously, the only thing that is obtained after sperm FISH studies is information, but this information could be very useful to the affected couple, to help them and the medical team, to choose among different possibilities of assisted reproduction methodologies

The goal of this study is to search for the January anomaly based on some economic theories and determining factors. By anomaly, we refer to any strange, unusual, or unique occurrence which deviates from established trends or economic principles. These economic theories attempt to explain the equilibrium and disequilibrium in the foreign exchange market. We aim at gauging when the SEK is likely to be misaligned and if an identified anomaly is evidence of a stable and long running phenomenon which an investment strategy could be based on, or whether it is just a short-term unique mispricing which will disappear in the long term. The research questions for this paper include:          What factors account for fluctuations in the Swedish Krona?          Is there evidence of a January effect in the Swedish Krona?   These questions will be evaluated based on the results of our computations on MS excel. Multiple regression analysis will be used to determine the level of significance for the monthly dummy variables. The exchange rates used in this paper include the SEK/€ and the SEK/$.

Thesis (M.S. in E.A.S.)--School of Earth and Atmospheric Sciences, Georgia Institute of Technology, 2004. Directed by James Gaherty. / Includes bibliographical references (leaves 38-42).

published_or_final_version / Physics / Master / Master of Philosophy