376 research outputs found

    A study of the age, growth, sexual maturity, and spawning of the anchoveta, Cetengraulis mysticetus, in the Gulf of Panama

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    ENGLISH: Crew members of tuna clippers and Commission personnel are collecting specimens of anchovetas (Cetengraulis mysticetus) for studies of the biology of this important tuna-bait species. More than 27,000 fish from 231 collections captured in the Gulf of Panama between June 1951 and January 1956 are the basis of this study of the age, growth, sexual maturity, and spawning season of this species in that area. Estimates of age and rate of growth were made by studying the temporal progression of modal size groups from monthly length frequency distributions. Sexual development and time of spawning were determined from gross examination of ovaries and measurements of ovarian eggs. SPANISH: Con el fin de estudiar la biología de la anchoveta (Cetengraulis mysticetus) los tripulantes de los barcos atuneros y el personal de la Comisión están recolectando especimenes de esta importante especie de carnada para capturar el atún. Mas de 27,000 ejemplares de las 231 colecciones hechas en el Golfo de Panamá entre junio de 1951 y enero de 1956, sirven de material al presente estudio sobre la edad, el crecimiento, la madurez sexual y las épocas de desove de esta especie en el área indicada. Las estimaciones de la edad y de la proporción del crecimiento fueron hechas a base del estudio de la progresión temporal de los grupos modales de tamaño en las distribuciones mensuales de frecuencias de longitud. El desarrollo sexual y el periodo de desove fueron determinados mediante el examen microscópico de los ovarios y las mediciones de los huevos ováricos. (PDF contains 79 pages.

    Studies of the age, growth, sexual maturity and spawning of populations of anchoveta (Cetengraulis mysticetus) of the coast of the Eastern Tropical Pacific Ocean

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    ENGLISH: Three hundred and twenty-six collections of anchoveta (Cetengraulis mysticetus), an important tuna bait species, taken between April 1951 and April 1960 from seven major baiting areas in the Eastern Tropical Pacific Ocean (Almejas Bay, Guaymas, Ahome Point, Banderas Bay, Gulf of Fonseca, coast of Colombia and Ecuador-Peru) are the basis of this study of age, growth, sexual maturity and spawning. The study of the temporal progression of modal size groups from plots of monthly length-frequency distributions provided estimates of age and rate of growth. The study of sexual maturity and time of spawning was based on gross examination of ovaries, and application of the gonad index. SPANISH: Trescientas veintiseis recolecciones de anchovetas (Cetengraulis mysticetus), una importante especie de carnada para la pesca del atún, cogidas entre abril de 1951 y abril de 1960 en siete de las mayores áreas de pesca de peces de carnada en el Océano Pacífico Oriental Tropical (Bahía de Almejas, Guaymas, Punta Ahome, Bahía Banderas, Golfo de Fonseca, y las costas de Colombia y de Ecuador- Perú), sirven de base a este estudio de la edad, crecimiento, madurez sexual y desove de dicha especie. El estudio de la progresión temporal de los grupos de tamaños modales según los gráficos de las distribuciones de la frecuencia de las longitudes proporcionó estimaciones de la edad y de la tasa de crecimiento. La investigación de la madurez sexual y la época de desove se basó en el examen macroscópico de los ovarios y en la aplicación del índice de gónadas.\u

    A study of populations of the anchoveta, Cetengraulis mysticetus, based on meristic characters

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    ENGLISH: This study was undertaken to determine whether meristic characters indicate that more than one major population of anchovetas occurs in the range of the species from Mexico to Peru. Interest in this species lies in the fact that it is the principal bait fish used to catch yellowfin and skipjack tunas in the Eastern Pacific. Specimens examined were from collections made by California tuna fishing vessels at six major baiting localities covering nearly the entire range of the species, namely, Almejas Bay on the outer coast of Baja California, Guaymas and Ahome Point in the Gulf of California, Gulf of Fonseca, Gulf of Panama, and Gulf of Guayaquil. Four meristic characters were selected for study: vertebrae, dorsal fin rays, anal fin rays, and gill rakers on the first gill arch. Vertebral counts, using X-ray film, were taken from a total of 1,500 fish, 250 each from each of the six localities. For the other characters, 125 anchovetas were examined from each locality for a total of 750, the counts being made with the aid of a binocular microscope. Specimens were between 80 and 165 mm. standard length. SPANISH: Este estudio ha sido hecho con el propósito de determinar si los caracteres numéricos de las anchovetas indican que existe más de una población de este pez en la zona en que se encuentra la especie, comprendida entre México y Perú. El interés en dicha especie radica en el hecho de que éste es el pez de carnada usado principalmente para la pesca de los atunes "aleta amarilla" y "barrilete" en el Pacífico Oriental. Los especímenes que han sido examinados, se tomaron de las muestras recogidas por los barcos atuneros de California en seis de las mejores localidades en que se pesca la anchoveta, las cuales comprenden casi toda la zona en donde se encuentra la especie, a saber, Bahía de Almejas en la costa exterior de Baja California, Guaymas y Punta Ahorne en el Golfo de California, el Golfo de Fonseca, el Golfo de Panamá y el Golfo de Guayaquil. Cuatro caracteres numéricos fueron escogidos para su estudio: los que presentan 1) las vértebras, 2) los radios de la aleta dorsal, 3) los radios de la aleta anal y 4) las branquispinas del primer arco branquial. Mediante el uso de películas con rayos X, se contaron las vértebras en un total de 1,500 peces, es decir, 250 de cada una de las seis mencionadas localidades. En relación con los otros caracteres, se examinaron 125 anchovetas de cada área, o sea, un total de 750 ejemplares, habiendo sido hecho el conteo por medio de un microscopio binocular. Los especímenes tenían un largo standard entre 80 y 165 milímetros. (PDF contains 24 pages.

    Some aspects of upwelling in the Gulf of Panama

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    ENGLISH: Strong coastal upwelling occurs in the Gulf of Panama regularly each year during the season, from about January through April, when strong northerly winds are blowing offshore. Because of the evident importance of upwelling to the ecology of the Gulf of Panama, we commenced in the fall of 1954 a study of various physical, chemical, and biological phenomena associated therewith. Observations were taken at bi-weekly intervals at a fixed location in the Gulf (approximately 10 miles SE of Taboga Island) to supplement the serial observations of sea level, sea temperature, and winds that have been gathered for many years by the Panama Canal Company. SPANISH: Cado año, en la estación de enero a abril, cuando los vientos del norte soplan vigorosamente frente a la costa, ocurre en el Golfo de Panamá un fuerte afloramiento costanero. Se cree que este afloramiento periódico en el Golfo de Panamá es responsable de la alta productividad biológica que sostiene considerables cantidades de organismos de importancia comercial. Esta región, por ejemplo, es una fuente importante de la especie Cetengraulis mysticetus) pez de carnada para el atún, (Alverson y Shimada, 1957) y mantiene una considerable pesca de camarones llamados langostinos (Burkenroad, Obarrio y Mendoza,1955). (PDF contains 54 pages.

    Imaging thiol redox status in murine tumors in vivo with rapid-scan electron paramagnetic resonance

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    Thiol redox status is an important physiologic parameter that affects the success or failure of cancer treatment. Rapid scan electron paramagnetic resonance (RS EPR) is a novel technique that has shown higher signal-to-noise ratio than conventional continuous-wave EPR in in vitro studies. Here we used RS EPR to acquire rapid three-dimensional images of the thiol redox status of tumors and normal tissues in living mice. This work presents, for the first time, in vivo RS EPR images of the kinetics of the reaction of 2H,15N-substituted disulfide-linked dinitroxide (PxSSPx) spin probe with intracellular glutathione. The cleavage rate is proportional to the intracellular glutathione concentration. Feasibility was demonstrated in a FSa fibrosarcoma tumor model in C3H mice. Similar to other in vivo and cell model studies, decreasing intracellular glutathione concentration by treating mice with L-buthionine sulfoximine (BSO) markedly altered the kinetic images

    'To live and die [for] Dixie': Irish civilians and the Confederate States of America

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    Around 20,000 Irishmen served in the Confederate army in the Civil War. As a result, they left behind, in various Southern towns and cities, large numbers of friends, family, and community leaders. As with native-born Confederates, Irish civilian support was crucial to Irish participation in the Confederate military effort. Also, Irish civilians served in various supporting roles: in factories and hospitals, on railroads and diplomatic missions, and as boosters for the cause. They also, however, suffered in bombardments, sieges, and the blockade. Usually poorer than their native neighbours, they could not afford to become 'refugees' and move away from the centres of conflict. This essay, based on research from manuscript collections, contemporary newspapers, British Consular records, and Federal military records, will examine the role of Irish civilians in the Confederacy, and assess the role this activity had on their integration into Southern communities. It will also look at Irish civilians in the defeat of the Confederacy, particularly when they came under Union occupation. Initial research shows that Irish civilians were not as upset as other whites in the South about Union victory. They welcomed a return to normalcy, and often 'collaborated' with Union authorities. Also, Irish desertion rates in the Confederate army were particularly high, and I will attempt to gauge whether Irish civilians played a role in this. All of the research in this paper will thus be put in the context of the Drew Gilpin Faust/Gary Gallagher debate on the influence of the Confederate homefront on military performance. By studying the Irish civilian experience one can assess how strong the Confederate national experiment was. Was it a nation without a nationalism

    Transdermal oestradiol for androgen suppression in prostate cancer: long-term cardiovascular outcomes from the randomised Prostate Adenocarcinoma Transcutaneous Hormone (PATCH) trial programme

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    Background Androgen suppression is a central component of prostate cancer management but causes substantial long-term toxicity. Transdermal administration of oestradiol (tE2) circumvents first-pass hepatic metabolism and, therefore, should avoid the cardiovascular toxicity seen with oral oestrogen and the oestrogen-depletion effects seen with luteinising hormone releasing hormone agonists (LHRHa). We present long-term cardiovascular follow-up data from the Prostate Adenocarcinoma Transcutaneous Hormone (PATCH) trial programme. Methods PATCH is a seamless phase 2/3, randomised, multicentre trial programme at 52 study sites in the UK. Men with locally advanced or metastatic prostate cancer were randomly allocated (1:2 from August, 2007 then 1:1 from February, 2011) to either LHRHa according to local practice or tE2 patches (four 100 μg patches per 24 h, changed twice weekly, reducing to three patches twice weekly if castrate at 4 weeks [defined as testosterone ≤1·7 nmol/L]). Randomisation was done using a computer-based minimisation algorithm and was stratified by several factors, including disease stage, age, smoking status, and family history of cardiac disease. The primary outcome of this analysis was cardiovascular morbidity and mortality. Cardiovascular events, including heart failure, acute coronary syndrome, thromboembolic stroke, and other thromboembolic events, were confirmed using predefined criteria and source data. Sudden or unexpected deaths were attributed to a cardiovascular category if a confirmatory post-mortem report was available and as other relevant events if no post-mortem report was available. PATCH is registered with the ISRCTN registry, ISRCTN70406718; the study is ongoing and adaptive. Findings Between Aug 14, 2007, and July 30, 2019, 1694 men were randomly allocated either LHRHa (n=790) or tE2 patches (n=904). Overall, median follow-up was 3·9 (IQR 2·4–7·0) years. Respective castration rates at 1 month and 3 months were 65% and 93% among patients assigned LHRHa and 83% and 93% among those allocated tE2. 157 events from 145 men met predefined cardiovascular criteria, with a further ten sudden deaths with no post-mortem report (total 167 events in 153 men). 26 (2%) of 1694 patients had fatal cardiovascular events, 15 (2%) of 790 assigned LHRHa and 11 (1%) of 904 allocated tE2. The time to first cardiovascular event did not differ between treatments (hazard ratio 1·11, 95% CI 0·80–1·53; p=0·54 [including sudden deaths without post-mortem report]; 1·20, 0·86–1·68; p=0·29 [confirmed group only]). 30 (34%) of 89 cardiovascular events in patients assigned tE2 occurred more than 3 months after tE2 was stopped or changed to LHRHa. The most frequent adverse events were gynaecomastia (all grades), with 279 (38%) events in 730 patients who received LHRHa versus 690 (86%) in 807 patients who received tE2 (p<0·0001) and hot flushes (all grades) in 628 (86%) of those who received LHRHa versus 280 (35%) who received tE2 (p<0·0001). Interpretation Long-term data comparing tE2 patches with LHRHa show no evidence of a difference between treatments in cardiovascular mortality or morbidity. Oestrogens administered transdermally should be reconsidered for androgen suppression in the management of prostate cancer. Funding Cancer Research UK, and Medical Research Council Clinical Trials Unit at University College London

    The state of the Martian climate

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    60°N was +2.0°C, relative to the 1981–2010 average value (Fig. 5.1). This marks a new high for the record. The average annual surface air temperature (SAT) anomaly for 2016 for land stations north of starting in 1900, and is a significant increase over the previous highest value of +1.2°C, which was observed in 2007, 2011, and 2015. Average global annual temperatures also showed record values in 2015 and 2016. Currently, the Arctic is warming at more than twice the rate of lower latitudes

    Genetic Variation in the HSD17B1 Gene and Risk of Prostate Cancer

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    Steroid hormones are believed to play an important role in prostate carcinogenesis, but epidemiological evidence linking prostate cancer and steroid hormone genes has been inconclusive, in part due to small sample sizes or incomplete characterization of genetic variation at the locus of interest. Here we report on the results of a comprehensive study of the association between HSD17B1 and prostate cancer by the Breast and Prostate Cancer Cohort Consortium, a large collaborative study. HSD17B1 encodes 17β-hydroxysteroid dehydrogenase 1, an enzyme that converts dihydroepiandrosterone to the testosterone precursor Δ5-androsterone-3β,17β-diol and converts estrone to estradiol. The Breast and Prostate Cancer Cohort Consortium researchers systematically characterized variation in HSD17B1 by targeted resequencing and dense genotyping; selected haplotype-tagging single nucleotide polymorphisms (htSNPs) that efficiently predict common variants in U.S. and European whites, Latinos, Japanese Americans, and Native Hawaiians; and genotyped these htSNPs in 8,290 prostate cancer cases and 9,367 study-, age-, and ethnicity-matched controls. We found no evidence that HSD17B1 htSNPs (including the nonsynonymous coding SNP S312G) or htSNP haplotypes were associated with risk of prostate cancer or tumor stage in the pooled multiethnic sample or in U.S. and European whites. Analyses stratified by age, body mass index, and family history of disease found no subgroup-specific associations between these HSD17B1 htSNPs and prostate cancer. We found significant evidence of heterogeneity in associations between HSD17B1 haplotypes and prostate cancer across ethnicity: one haplotype had a significant (p < 0.002) inverse association with risk of prostate cancer in Latinos and Japanese Americans but showed no evidence of association in African Americans, Native Hawaiians, or whites. However, the smaller numbers of Latinos and Japanese Americans in this study makes these subgroup analyses less reliable. These results suggest that the germline variants in HSD17B1 characterized by these htSNPs do not substantially influence the risk of prostate cancer in U.S. and European whites
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