Actividades Pesqueras de Mexico en 1938

Catch statistics for Mexican waters 1938. (PDF has 181 pages.)

Oceanographic, meteorological, satellite and aircraft observations for project Little Window 2: May 1971

ENGLISH: In May 1971, a joint united states - Mexican experiment, Project Little Window 2, (LW-2) involving data collected by satellite, aircraft and ship sensors was made in the southern part of the Gulf of California. LW-2 was planned as an improved and enlarged version of LW-l (conducted the previous year; Stevenson and Miller, 1971) with field work scheduled to be made within a 200 by 200 km square region in the Gulf of California. The purposes of the new field study were to determine through coordinated measurements from ships, aircraft and satellites, the utility of weather satellites to measure surface temperature features of the ocean from space and specifically to evaluate the high resolution infrared sensors aboard N~ 1, ITOS 1 and NIMBUS 4 and to estimate the magnitude of the atmospheric correction factors needed to bring the data from the spacecraft sensors into agreement with surface measurements. Due to technical problems during LW-2, however, useful data could not be obtained from ITOS 1 and NIMBUS 4 so satellite information from only NOAA-1 was available for comparison. In addition, a new purpose was added, i.e., to determine the feasibility of using an Automatic picture Transmission (APT) receiver on shore and at sea to obtain good quality infrared data for the local region. SPANISH: En mayo 1971, los Estados Unidos y México realizaron un experimento en conjunto, Proyecto Little Window 2 (LW-2), en el que se incluyen datos obtenidos mediante captadores de satélites, aviones y barcos en la parte meridional del Golfo de California. Se planeó LW-2 para mejorar y ampliar el proyecto de LW-l (conducido el año anterior; Stevenson y Miller, 1971), realizándose el trabajo experimental en una región de 200 por 200 km cuadrados, en el Golfo de California. El objeto de este nuevo estudio experimental fue determinar mediante reconocimientos coordinados de barcos, aviones y satélites la conveniencia de los satélites meteorológicos para averiguar las características de la temperatura superficial del océano desde el espacio, y especialmente, evaluar los captadores infrarrojos de alta resolución a bordo de NOAA 1, ITOS 1 Y NIMBUS 4, y estimar la magnitud de los factores de corrección atmosféricos necesarios para corregir los datos de los captadores espaciales para que concuerden con los registros de la superficie. Sin embargo, debido a problemas técnicos durante LW-2, no fue posible obtener datos adecuados de ITOS 1 y NIMBUS 4, as1 que solo se pudo disponer de la información de NOAA 1 para hacer las comparaciones. Además se quiso determinar la posibilidad de usar un receptor de Trasmisión Automático de Fotografias (APT) en el mar para obtener datos infarojos de buena calidad en la región local. (PDF contains 525 pages.)

Report of the Inter-American Tropical Tuna Commission for the year 1964

ENGLISH: The Inter-American Tropical Tuna Commission operates under the authority and direction of a Convention originally negotiated between the Republic of Costa Rica and the United States of America, which entered into force in 1950. The Convention is open to adherence by other governments whose nationals participate in the fisheries covered by the Convention. Under this provision, the Republic of Panama adhered in 1953, the Republic of Ecuador in 1961 and the United Mexican States in 1964. SPANISH: La Comisión Interamericana del Atún Tropical funciona bajo la autoridad y dirección de una Convención negociada originalmente entre la República de Costa Rica y los Estados Unidos de América, la cuál entró en vigencia en 1950. La Convención está abierta a la adhesión de los gobiernos de otros países cuyos ciudadanos participan en las pesquerías objeto de la Convención. Acogiéndose a esta cláusula, la República de Panamá se adhirió a la Convención en 1953, la República de Ecuador en 1961 y los Estados Unidos Mexicanos en 1964. (PDF contains 98 pages.)

Report of the Inter-American Tropical Tuna Commission for the year 1966

ENGLISH: The Inter-American Tropical Tuna Commission operates under the authority and direction of a Convention originally entered into by the Republic of Costa Rica and the United States of America. The Convention, which came into force in 1950, is open to adherence by other governments whose nationals participate in the fisheries covered by the Convention. Under this provision the Republic of Panama adhered in 1953, the Republic of Ecuador in 1961, and the United Mexican States in 1964. SPANISH: La Comisión Interamericana del Atún Tropical funciona bajo la autoridad y dirección de una Convención formada originalmente entre la República de Costa Rica y los Estados Unidos de América. La Convención entró en vigencia en 1950, está abierta a la adhesión de otros gobiernos cuyos ciudadanos participen en las pesquerías objeto de la Convención. Bajo esta cláusula, la República de Panamá se adhirió en 1953, la República del Ecuador en 1961 y los Estados Unidos Mexicanos en 1964. (PDF contains 138 pages.)

Report of the Inter-American Tropical Tuna Commission for the year 1967

ENGLISH: The Inter-American Tropical Tuna Commission was created and operates under the authority of a Convention first negotiated between the governments of the Republic of Costa Rica and the United States of America. The Convention entered into force in 1950. It is open to adherence by other governments whose nationals fish for tunas in the eastern Pacific area. Under this provision, Panama adhered in 1953, Ecuador in 1961, the United Mexican States in 1964. Canada applied for membership in 1967. Her membership will become effective on April 1, 1968. On August 21, 1967 the Ecuadorian government, for financial reasons, elected to withdraw from active membership. Under Convention ruling, this means that she remains a full member until August 21, 1968. SPANISH: La Comisión Interamericana del Atún Tropical fue originada y está bajo la autoridad de una Convención que fue negociada inicialmente entre los gobiernos de la República de Costa Rica y los Estados Unidos de América. La Convención entró en vigencia en 1950. Está abierta a la afiliación de otros gobiernos cuyos ciudadanos pescan atunes en el área del Pacífico oriental. Bajo esta estipulación, Panamá se afilió en 1953, Ecuador en 1961 y los Estados Unidos Mexicanos en 1964. Canadá presentó su ap1licación en 1967. Su afiliación será efectiva el 1 de abril de 1968. El 21 de agosto de 1967, el gobierno ecuatoriano por razones financieras decidió retirar su participación activa. Bajo las reglas de la Convención el Ecuador sigue actuando como miembro hasta el 21 de agosto de 1968. (PDF contains 144 pages.)

Report of the Inter-American Tropical Tuna Commission for the year 1968

ENGLISH: The Inter-American Tropical Tuna Commission operates under the authority and direction of a Convention originally entered into by the Republic of Costa Rica and the United States of America. The Convention, which came into force in 1950, is open to adherence by other governments whose nationals fish in the eastern tropical Pacific. Under this provision the Republic of Panama adhered in 1953, the Republic of Ecuador in 1961, the United Mexican States in 1964 and Canada in 1968. In 1967 Ecuador gave notice of her intent to withdraw from the Commission and her withdrawal became effective on August 21, 1968. SPANISH:La Comisión Interamericana del Atún Tropical está bajo la autoridad y dirección de una Convención la cual fue originalmente formada por la República de Costa Rica y los Estados Unidos de América. La Convención, vigente desde 1950, está abierta a la afiliación de otros gobiernos cuyos nacionales pesquen en. el Pacífico oriental tropical. Bajo esta medida la República de Panamá se afilió en 1953, la. República del Ecuador en 1961, los Estados Unidos Mexicanos en 1964 y' el Canadá en 19Ei8. En 1967, el Ecuador anunció su intención de retirarse de la Comisión y la resignación se hizo efectiva el 21 de agosto de 1968. (PDF contains 128 pages.)

Report of the Inter-American Tropical Tuna Commission for the year 1969

ENGLISH: The Inter-American Tropical Tuna Commission operates under the authority and direction of a convention originally entered into by the Republic of Costa Rica and the United States of America. The convention, which came into force in 1950, is open to adherence by other governments whose nationals fish for tropical tunas in the eastern Pacific Ocean. Under this provision the Republic of Panama adhered in 1953, the Republic of Ecuador in 1961, the United Mexican States in 1964 and Canada in 1968. In 1967, Ecuador gave notice of her intent to withdraw from the Commission, and her withdrawal became effective on August 21, 1968. SPANISH: La Comisión Interamericana del Atún Tropical está bajo la autoridad y dirección de una convención la cual fue originalmente formada por la República de Costa Rica y los Estados Unidos de América. La Convención, vigente desde 1950, está abierta a la afiliación de otros gobiernos cuyos nacionales pesquen túnidos en el Pacifico oriental tropical. Bajo esta medida la República de Panamá se afilió en 1953, la República del Ecuador en 1961, los Estados Unidos Mexicanos en 1964, y Canadá en 1968. En 1967, el Ecuador anunció su intención de retirarse de la Comisión y la renuncia se hizo efectiva el 21 de agosto de 1968. (PDF contains 117 pages.)

Report of the Inter-American Tropical Tuna Commission for the year 1970

ENGLISH: The Inter-American Tropical Tuna Commission operates under the authority and direction of a convention originally entered into by the Republic of Costa Rica and the United States of America. The convention, which came into force in 1950, is open to adherence by other governments whose nationals fish for tropical tunas in the eastern Pacific Ocean. Under this provision the Republic of Panama adhered in 1953, the Republic of Ecuador in 1961, the United Mexican States in 1964, Canada in 1968 and Japan in 1970. In 1967, Ecuador gave notice of her intent to withdraw from the Commission, and her withdrawal became effective on August 21, 1968. SPANISH:La Comisión Interamericana del Atún Tropical está bajo la autoridad y dirección de una convención la cual fue originalmente formada por la República de Costa Rica y los Estados Unidos de América. La Convención, vigente desde 1950, está abierta a la afiliación de otros gobiernos cuyos nacionales pesquen atún en el Pacífico oriental tropical. Bajo esta medida la República de Panamá se afilió en 1953, la República del Ecuador en 1961, los Estados Unidos Mexicanos en 1964, Canadá en 1968 y el Japón en 1970. En 1967, el Ecuador anunció su intención de retirarse de la Comisión y la renuncia se hizo efectiva el 21 de agosto de 1968. (PDF contains 128 pages.)

Report of the Inter-American Tropical Tuna Commission for the year 1971

ENGLISH: The Inter-American Tropical Tuna Commission operates under the authority and direction of a convention originally entered into by the Republic of Costa Rica and the United States of America. The convention, which came into force in 1950, is open to adherence by other governments whose nationals fish for tropical tunas in the eastern Pacific Ocean. Under this provision the Republic of Panama adhered in 1953, the Republic of Ecuador in 1961, the United Mexican States in 1964, Canada in 1968 and Japan in 1970. In 1967, Ecuador gave notice of her intent to withdraw from the Commission, and her withdrawal became effective on August 21,1968. SPANISH: La Comisión Interamericana del Atún Tropical está bajo la autoridad y dirección de una convención la cual fue originalmente formada por la República de Costa Rica y los Estados Unidos de América. La Convención, vigente desde 1950, está abierta a la afiliación de otros gobiernos cuyos nacionales pesquen atún en el Pacífico oriental tropical. Bajo esta medida la República de Panamá se afilió en 1953, la República del Ecuador en 1961, los Estados Unidos Mexicanos en 1964, Canadá en 1968 y el Japón en 1970. En 1967, el Ecuador anunció su intención de retirarse de la Comisión y la renuncia se hizo efectiva el 21 de agosto de 1968. (PDF contains 127 pages.)

Plate tectonic constraints on flat subduction and paleomagnetic constraints on rifting

Plate tectonics shapes our dynamic planet through the creation and destruction of lithosphere. This work focuses on increasing our understanding of the processes at convergent and divergent boundaries through geologic and geophysical observations at modern plate boundaries. Recent work had shown that the subducting slab in central Mexico is most likely the flattest on Earth, yet there was no consensus about what caused it to originate. The first chapter of this thesis sets out to systematically test all previously proposed mechanisms for slab flattening on the Mexican case. What we have discovered is that there is only one model for which we can find no contradictory evidence. The lack of applicability of the standard mechanisms used to explain flat subduction in the Mexican example led us to question their applications globally. The second chapter expands the search for a cause of flat subduction, in both space and time. We focus on the historical record of flat slabs in South America and look for a correlation between the shallowing and steepening of slab segments with relation to the inferred thickness of the subducting oceanic crust. Using plate reconstructions and the assumption that a crustal anomaly formed on a spreading ridge will produce two conjugate features, we recreate the history of subduction along the South American margin and find that there is no correlation between the subduction of a bathymetric highs and shallow subduction. These studies have proven that a subducting crustal anomaly is neither a sufficient or necessary condition of flat slab subduction. The final chapter in this thesis looks at the divergent plate boundary in the Gulf of California. Through geologic reconnaissance mapping and an intensive paleomagnetic sampling campaign, we try to constrain the location and orientation of a widespread volcanic marker unit, the Tuff of San Felipe. Although the resolution of the applied magnetic susceptibility technique proved inadequate to contain the direction of the pyroclastic flow with high precision, we have been able to detect the tectonic rotation of coherent blocks as well as rotation within blocks.

Oceanographic Profiling and Spectroradiometer Observations from the MOCE-2 Cruise: 28 March to 14 April 1993

This report contains results from the second cruise of the Modis Optical Characterization Experiment (MOCE). Data presented here were obtained on the Mexican Research Vessel El Puma between 29 March and 13 April along the Pacific coast of Baja California and in the Gulf of California. Three types of data are reported: high spectral resolution radiometry at three depths for 13 stations; salinity, temperature beam attenuation and chlorophyll-a fluorescence, profiles at the same stations; and total suspended matter and suspended organic carbon and nitrogen.(PDF is 90 pages.)

Statistical and econometric analysis of the treatment of HIV/AIDS

The epidemic of HIV/AIDS in the United States is constantly changing and evolving, starting from patient zero to now an estimated 650,000 to 900,000 Americans infected. The nature and course of HIV changed dramatically with the introduction of antiretrovirals. This discourse examines many different facets of HIV from the beginning where there wasn't any treatment for HIV until the present era of highly active antiretroviral therapy (HAART). By utilizing statistical analysis of clinical data, this paper examines where we were, where we are and projections as to where treatment of HIV/AIDS is headed.

Chapter Two describes the datasets that were used for the analyses. The primary database utilized was collected by myself from an outpatient HIV clinic. The data included dates from 1984 until the present. The second database was from the Multicenter AIDS Cohort Study (MACS) public dataset. The data from the MACS cover the time between 1984 and October 1992. Comparisons are made between both datasets.

Chapter Three discusses where we were. Before the first anti-HIV drugs (called antiretrovirals) were approved, there was no treatment to slow the progression of HIV. The first generation of antiretrovirals, reverse transcriptase inhibitors such as AZT (zidovudine), DDI (didanosine), DDC (zalcitabine), and D4T (stavudine) provided the first treatment for HIV. The first clinical trials showed that these antiretrovirals had a significant impact on increasing patient survival. The trials also showed that patients on these drugs had increased CD4+ T cell counts. Chapter Three examines the distributions of CD4 T cell counts. The results show that the estimated distributions of CD4 T cell counts are distinctly non-Gaussian. Thus distributional assumptions regarding CD4 T cell counts must be taken, into account when performing analyses with this marker. The results also show the estimated CD4 T cell distributions for each disease stage: asymptomatic, symptomatic and AIDS are non-Gaussian. Interestingly, the distribution of CD4 T cell counts for the asymptomatic period is significantly below that of the CD4 T cell distribution for the uninfected population suggesting that even in patients with no outward symptoms of HIV infection, there exists high levels of immunosuppression.

Chapter Four discusses where we are at present. HIV quickly grew resistant to reverse transcriptase inhibitors which were given sequentially as mono or dual therapy. As resistance grew, the positive effects of the reverse transcriptase inhibitors on CD4 T cell counts and survival dissipated. As the old era faded a new era characterized by a new class of drugs and new technology changed the way that we treat HIV-infected patients. Viral load assays were able to quantify the levels of HIV RNA in the blood. By quantifying the viral load, one now had a faster, more direct way to test antiretroviral regimen efficacy. Protease inhibitors, which attacked a different region of HIV than reverse transcriptase inhibitors, when used in combination with other antiretroviral agents were found to dramatically and significantly reduce the HIV RNA levels in the blood. Patients also experienced significant increases in CD4 T cell counts. For the first time in the epidemic, there was hope. It was hypothesized that with HAART, viral levels could be kept so low that the immune system as measured by CD4 T cell counts would be able to recover. If these viral levels could be kept low enough, it would be possible for the immune system to eradicate the virus. The hypothesis of immune reconstitution, that is bringing CD4 T cell counts up to levels seen in uninfected patients, is tested in Chapter Four. It was found that for these patients, there was not enough of a CD4 T cell increase to be consistent with the hypothesis of immune reconstitution.

In Chapter Five, the effectiveness of long-term HAART is analyzed. Survival analysis was conducted on 213 patients on long-term HAART. The primary endpoint was presence of an AIDS defining illness. A high level of clinical failure, or progression to an endpoint, was found.

Chapter Six yields insights into where we are going. New technology such as viral genotypic testing, that looks at the genetic structure of HIV and determines where mutations have occurred, has shown that HIV is capable of producing resistance mutations that confer multiple drug resistance. This section looks at resistance issues and speculates, ceterus parabis, where the state of HIV is going. This section first addresses viral genotype and the correlates of viral load and disease progression. A second analysis looks at patients who have failed their primary attempts at HAART and subsequent salvage therapy. It was found that salvage regimens, efforts to control viral replication through the administration of different combinations of antiretrovirals, were not effective in 90 percent of the population in controlling viral replication. Thus, primary attempts at therapy offer the best change of viral suppression and delay of disease progression. Documentation of transmission of drug-resistant virus suggests that the public health crisis of HIV is far from over. Drug resistant HIV can sustain the epidemic and hamper our efforts to treat HIV infection. The data presented suggest that the decrease in the morbidity and mortality due to HIV/AIDS is transient. Deaths due to HIV will increase and public health officials must prepare for this eventuality unless new treatments become available. These results also underscore the importance of the vaccine effort.

The final chapter looks at the economic issues related to HIV. The direct and indirect costs of treating HIV/AIDS are very high. For the first time in the epidemic, there exists treatment that can actually slow disease progression. The direct costs for HAART are estimated. It is estimated that the direct lifetime costs for treating each HIV infected patient with HAART is between $353,000 to $598,000 depending on how long HAART prolongs life. If one looks at the incremental cost per year of life saved it is only $101,000. This is comparable with the incremental costs per year of life saved from coronary artery bypass surgery.

Policy makers need to be aware that although HAART can delay disease progression, it is not a cure and HIV is not over. The results presented here suggest that the decreases in the morbidity and mortality due to HIV are transient. Policymakers need to be prepared for the eventual increase in AIDS incidence and mortality. Costs associated with HIV/AIDS are also projected to increase. The cost savings seen recently have been from the dramatic decreases in the incidence of AIDS defining opportunistic infections. As patients who have been on HAART the longest start to progress to AIDS, policymakers and insurance companies will find that the cost of treating HIV/AIDS will increase.

Seismic structure along transitions from flat to normal subduction: central Mexico, southern Peru, and southwest Japan

The fine-scale seismic structure of the central Mexico, southern Peru, and southwest Japan subduction zones is studied using intraslab earthquakes recorded by temporary and permanent regional seismic arrays. The morphology of the transition from flat to normal subduction is explored in central Mexico and southern Peru, while in southwest Japan the spatial coincidence of a thin ultra-slow velocity layer (USL) atop the flat slab with locations of slow slip events (SSEs) is explored. This USL is also observed in central Mexico and southern Peru, where its lateral extent is used as one constraint on the nature of the flat-to-normal transitions.

In western central Mexico, I find an edge to this USL which is coincident with the western boundary of the projected Orozco Fracture Zone (OFZ) region. Forward modeling of the 2D structure of the subducted Cocos plate using a finite-difference algorithm provides constraints on the velocity and geometry of the slab’s seismic structure in this region and confirms the location of the USL edge. I propose that the Cocos slab is currently fragmenting into a North Cocos plate and a South Cocos plate along the projection of the OFZ, by a process analogous to that which occurred when the Rivera plate separated from the proto-Cocos plate 10 Ma.

In eastern central Mexico, observations of a sharp transition in slab dip near the abrupt end of the Trans Mexican Volcanic Belt (TMVB) suggest a possible slab tear located within the subducted South Cocos plate. The eastern lateral extent of the USL is found to be coincident with these features and with the western boundary of a zone of decreased seismicity, indicating a change in structure which I interpret as evidence of a possible tear. Analysis of intraslab seismicity patterns and focal mechanism orientations and faulting types provides further support for a possible tear in the South Cocos slab. This potential tear, together with the tear along the projection of the OFZ to the northwest, indicates a slab rollback mechanism in which separate slab segments move independently, allowing for mantle flow between the segments.

In southern Peru, observations of a gradual increase in slab dip coupled with a lack of any gaps or vertical offsets in the intraslab seismicity suggest a smooth contortion of the slab. Concentrations of focal mechanisms at orientations which are indicative of slab bending are also observed along the change in slab geometry. The lateral extent of the USL atop the horizontal Nazca slab is found to be coincident with the margin of the projected linear continuation of the subducting Nazca Ridge, implying a causal relationship, but not a slab tear. Waveform modeling of the 2D structure in southern Peru provides constraints on the velocity and geometry of the slab’s seismic structure and confirms the absence of any tears in the slab.

In southwest Japan, I estimate the location of a possible USL along the Philippine Sea slab surface and find this region of low velocity to be coincident with locations of SSEs that have occurred in this region. I interpret the source of the possible USL in this region as fluids dehydrated from the subducting plate, forming a high pore-fluid pressure layer, which would be expected to decrease the coupling on the plate interface and promote SSEs.

Freshwater biological research in Mexico: A brief historical review

Apart from a couple of early papers in the 1600s, the development of freshwater biology as a science in Mexico began in the last century. Taxonomic studies were made especially on algae, aquatic insects, crustaceans, annelid worms and aquatic plants. The great impetus acquired by limnology in Europe and America in the first half of the 20th Century stimulated foreign researchers to come and work in Mexico. During this period the Instituto de Biologia, belonging to the Universidad Nacional Autonoma de Mexico, was created in 1930. The Institute had a section of Hydrobiology that contributed to the limnological characterization of Mexican lakes and ponds. In 1962, the Instituto Nacional de Investigaciones Biologico-Pesqueras was created to bring together the work of several institutes working on the native ichthyofauna, the restocking of reservoirs, and aquaculture.

The lakes of Michoacan (Mexico): A brief history and alternative point of view

This article is intended to open a discussion about the historical development of lakes Zirahuen, Patzcuaro and Cuitzeo in the state of Michoacan, and the postulated relationships between lake ecology and evolution. Dr Fernando De Buen was the first man dedicated to limnology in Mexico who came to the country in the 1930s. He was adviser at the Estacion Limnologica de Patzcuaro and wrote outstanding papers dealing with Mexican lakes. The lakes of Michoacan probably formed in the late Pliocene or Holocene, and were part of a tributary to the Lerma River, which became isolated by successive volanic barriers to form lake basins. Lake Zirahuen is a warm monomictic waterbody with unique water dynamics amongst the Michoacan lakes. Because it is relatively deep (max depth 40m), seasonal patterns of alternating circulation and thermal stratification develop in the lake, a feature not shared by the other two polymictic shallow lakes, Patzcuaro and Cuitzeo.