2,418 research outputs found

    Seasonal changes in growth of coho salmon (Oncorhynchus kisutch) off Oregon and Washington and concurrent changes in the spacing of scale circuli

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    In this study we present new information on seasonal variation in absolute growth rate in length of coho salmon (Oncorhynchus kisutch) in the ocean off Oregon and Washington, and relate these changes in growth rate to concurrent changes in the spacing of scale circuli. Average spacing of scale circuli and average rate of circulus formation were significantly and positively correlated with average growth rate among groups of juvenile and maturing coho salmon and thus could provide estimates of growth between age groups and seasons. Regression analyses indicated that the spacing of circuli was proportional to the scale growth rate raised to the 0.4−0.6 power. Seasonal changes in the spacing of scale circuli reflected seasonal changes in apparent growth rates of fish. Spacing of circuli at the scale margin was greatest during the spring and early summer, decreased during the summer, and was lowest in winter or early spring. Changes over time in length of fish caught during research cruises indicated that the average growth rate of juvenile coho salmon between June and September was about 1.3 mm/d and then decreased during the fall and winter to about 0.6 mm/d. Average growth rate of maturing fish was about 2 mm/d between May and June, then decreased to about 1 mm/d between June and September. Average apparent growth rates of groups of maturing coded-wire−tagged coho salmon caught in the ocean hook-and-line fisheries also decreased between June and September. Our results indicate that seasonal change in the spacing of scale circuli is a useful indicator of seasonal change in growth rate of coho salmon in the ocean

    Ocean distribution of the American shad (Alosa sapidissima) along the Pacific coast of North America

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    We examined the incidental catches of American shad (Alosa sapidissima) taken during research cruises and in commercial and recreational landings along the Pacific coast of North America during over 30 years of sampling. Shad, an introduced species, was mainly found over the shallow continental shelf, and largest catches and highest frequency of occurrences were found north of central Oregon, along the coasts of Washington and Vancouver Island, and in California around San Francisco Bay. Migrations to the north off Washington and Vancouver were seen during spring to fall, but we found no evidence for large-scale seasonal migrations to the south during the fall or winter. The average weight of shad increased in deeper water. Sizes were also larger in early years of the study. Most were caught over a wide range of sea surface temperatures (11–17°C) and bottom temperatures (6.4–8.0°C). Abundance of shad on the continental shelf north of 44°N was highly correlated with counts of shad at Bonneville Dam on the Columbia River in the same year. Counts were negatively related to average weights and also negatively correlated with the survival of hatchery coho salmon (Oncorhynchus kisutch), indicating that survival of shad is favored by warm ocean conditions. Examining the catch during research cruises and commercial and recreational landings, we concluded that American shad along the Pacific coast have adapted to the prevailing environmental conditions and undertake only moderate seasonal migrations compared with the long seasonal migrations of shad along the Atlantic coast of North America. We suggest that the large spawning populations in the Columbia River and San Francisco Bay areas explain most of the distributional features along the Pacific coast

    Distribution and Abundance of Juvenile Salmonids off Oregon and Washington, 1981-1985

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    This report is a summary of the results of 883 purse seine sets made for juvenile salmonids during 15 cruises off the coasts of Oregon and Washington during the springs and summers of 1981-1985. Juvenile coho salmon (Oncorhynchus kisutch) occurred most frequently, followed by chinook salmon (0. tshawytscha). The juveniles of these two species co-occurred more frequently than expected. Juvenile chum, pink and sockeye salmon (0. keta, O. gorbuscha, and O. nerka), steelhead (0. mykiss) and cutthroat trout (0. clarki clarki) were caught much less frequently and in lower numbers than coho or chinook salmon. We found no evidence of large schools ofjuvenile salmonids. A northerly movement of juvenile coho salmon wa~ suggested by decreased catches off Oregon and increased catches off Washington between early and late summer. Highest catch per set of juvenile coho salmon was usually found inshore of 37.2 km. Juvenile chinook salmon were usually found within 27.9 km of the coast. Juvenile salmonids were found over a broad range of surface salinities and temperatures. High catches of juvenile coho salmon occurred in both the low salinity waters of the Columbia River plume and in adjacent higher salinity waters. Preferences for specific salinities or temperatures were not obvious for any species, although catch rates of juvenile coho salmon were highest in years when chlorophyll content was also high. Based on expansions of fish with coded wire tags, we estimated that hatchery coho salmon smolts comprised 74%, on average, of the juvenile coho salmon catches. The remaining 26% were presumably wild fish or hatchery fish released as fingerlings. Hatchery coho salmon were caught roughly in proportion to the numbers released. However, hatchery fish from the Columbia River and private coastal facilities were caught at slightly higher rates while those from coastal Washington and public coastal Oregon hatcheries were caught at slightly lower rates than expected from the numbers released. No juvenile coho salmon with coded wire tags were caught that had originated from either California or Puget Sound hatcheries. (PDF file contains 88 pages.

    A Case Report: The Myxomatous Mystery

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    Introduction: Primary cardiac tumors are rare with an incidence rate of 1.38 new cases per 100,000 individuals per year. Of these tumors, 75% are benign in origin and the most common type is a myxoma with a frequency of over 50%. Myxomas most commonly arise from the left atrium followed by the right atrium. Clinical presentation of a myxoma varies depending on the location, size, and shape of the tumor. For example, a patient diagnosed with a myxoma may have constitutional symptoms, cardiovascular symptoms, pulmonary symptoms etc. or may be entirely asymptomatic. Since there is no specific symptoms presented by patients with a myxoma, physicians often face challenges in diagnosing. Case Presentation: A 72-year-old female with a past medical history of hypertension presented to the Emergency Department (ED) with progressive dyspnea on exertion of 1-week duration. She reported chest tightness, orthopnea, and paroxysmal nocturnal dyspnea. She denied experiencing similar symptoms in the past. Vital signs were unremarkable except for her blood pressure which was 178/103 mm Hg. Pertinent physical exam findings included jugular venous distension, a S3 heart sound, and bibasilar rales. Laboratory tests were ordered and all were unremarkable, including her troponin I and BNP levels. ECG was significant for T wave inversion in the inferior leads. Chest x-ray and CT were ordered and showed diffuse ground glass opacities throughout both lungs, bilateral pleural effusions, and mild cardiomegaly, as well as dilation of the main pulmonary artery. Lasix was given as patient appeared to be volume overloaded which resulted in brisk diuresis and relief of symptoms. At this point, an acute exacerbation of left-sided heart failure was suspected and a transthoracic echocardiogram (TTE) was ordered. TTE revealed a large ovoid mobile echodense mass. The mass was 5.1 cm x 2.9 cm and attached to the lower half of the interatrial septum on the left atrium and moved in and out of the left ventricular inflow. This finding was most consistent with a left atrial myxoma and the patient was then transferred to a medical center capable of resecting the myxoma. The patient tolerated the myxoma excision well and was discharged to cardiac rehabilitation. The surgical pathology report confirmed cardiac myxoma with central hemorrhage. Discussion: In the setting of predisposed hypertension, we suspect that the large size and mobile nature of the left atrial myxoma caused functional partial obstruction of the mitral valve, leading to secondary valvular heart disease and eventually progressive left-sided heart failure. Despite the rarity of the disease, myxomas as well as other cardiac tumors should always be included in the differential diagnosis when a patient presents with symptoms suspected of an acute exacerbation of heart failure. Echocardiogram is the diagnostic modality of choice to utilize when a myxoma is suspected

    Thinning of superfluid films below the critical point

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    Experiments on 4^4He films reveal an attractive Casimir-like force at the bulk λ\lambda-point, and in the superfluid regime. Previous work has explained the magnitude of this force at the λ\lambda transition and deep in the superfluid region but not the substantial attractive force immediately below the λ\lambda-point. Utilizing a simple mean-field calculation renormalized by critical fluctuations we obtain an effective Casimir force that is qualitatively consistent with the scaling function ϑ\vartheta obtained by collapse of experimental data.Comment: 4 page

    Undiagnosed Diabetes and Pre-Diabetes in Health Disparities

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    Globally half of all diabetes mellitus is undiagnosed. We sought to determine the extent and characteristics of undiagnosed type 2 diabetes mellitus and pre-diabetes in Mexican Americans residing in the United States. This disadvantaged population with 50% lifetime risk of diabetes is a microcosm of the current pandemic. We accessed baseline data between 2004 and 2014 from 2,838 adults recruited to our Cameron County Hispanic Cohort (CCHC); a two-stage randomly selected \u27Framingham-like\u27 cohort of Mexican Americans on the US Mexico border with severe health disparities. We examined prevalence, risk factors and metabolic health in diagnosed and undiagnosed diabetes and pre-diabetes. Two thirds of this Mexican American population has diabetes or pre-diabetes. Diabetes prevalence was 28.0%, nearly half undiagnosed, and pre-diabetes 31.6%. Mean BMI among those with diabetes was 33.5 kg/m2 compared with 29.0 kg/m2 for those without diabetes. Significant risk factors were low income and educational levels. Most with diabetes had increased waist/hip ratio. Lack of insurance and access to health services played a decisive role in failure to have diabetes diagnosed. Participants with undiagnosed diabetes and pre-diabetes had similar measures of poor metabolic health similar but generally not as severe as those with diagnosed diabetes. More than 50% of a minority Mexican American population in South Texas has diabetes or pre-diabetes and is metabolically unhealthy. Only a third of diabetes cases were diagnosed. Sustained efforts are imperative to identify, diagnose and treat individuals in underserved communities

    Transition from pre-diabetes to diabetes and predictors of risk in Mexican-Americans

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    Background: No studies have examined risk factors for the transition from pre-diabetes to diabetes in populations with widespread obesity and diabetes. We determined proximal changes and factors affecting the transition among Mexican-Americans with pre-diabetes. Methods: Participants with pre-diabetes (n=285) were recruited from our randomly sampled population-based Cameron County Hispanic Cohort. These participants were followed for an average of 27 months with repeat examination every 3 to 4 months. Metabolic health was defined as having less than 2 metabolic abnormalities (e.g., hypertension, elevated low-density lipoprotein, etc). Diabetes was identified as fasting blood glucose ≥126 mg/dL, glycated hemoglobin ≥6.5% and/or on hypoglycemic medication. Results: Ninety-six of 285 (33.7%) participants transitioned to overt diabetes. The increased risk of diabetes in the metabolically unhealthy varying with follow-up time was 81% (adjusted odds ratio [OR]: 1.81; 95% CI: 1.09–3.02). The risk of diabetes increased 8% for each kg/m2 of increase in body mass index (BMI, OR: 1.08; 95% CI: 1.05–1.11) independent of covariates. Transition to diabetes was accompanied by a mean increase in BMI of 0.28 kg/m2, and deterioration in metabolic health of 9% (OR: 1.09; 95% CI: 1.003–1.18) compared with those who did not transition. Conclusions: Deteriorating metabolic health and/or increasing BMI significantly raises the risk of transitioning from pre-diabetes to diabetes. Transition itself was accompanied by further increase in BMI and deterioration in metabolic health. These data underline the importance of improving metabolic health and avoiding weight gain in pre-diabetes as simple but clear diabetes prevention targets, and emphasize the importance of lifestyle management

    Metabolic Health Has Greater Impact on Diabetes than Simple Overweight/Obesity in Mexican Americans

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    To compare the risk for diabetes in each of 4 categories of metabolic health and BMI. Methods. Participants were drawn from the Cameron County Hispanic Cohort, a randomly selected Mexican American cohort in Texas on the US-Mexico border. Subjects were divided into 4 phenotypes according to metabolic health and BMI: metabolically healthy normal weight, metabolically healthy overweight/obese, metabolically unhealthy normal weight, and metabolically unhealthy overweight/obese. Metabolic health was defined as having less than 2 metabolic abnormalities. Overweight/obese status was assessed by BMI higher than 25 kg/m2. Diabetes was defined by the 2010 ADA definition or by being on a diabetic medication. Results. The odds ratio for diabetes risk was 2.25 in the metabolically healthy overweight/obese phenotype (95% CI 1.34, 3.79), 3.78 (1.57, 9.09) in the metabolically unhealthy normal weight phenotype, and 5.39 (3.16, 9.20) in metabolically unhealthy overweight/obese phenotype after adjusting for confounding factors compared with the metabolically healthy normal weight phenotype. Conclusions. Metabolic health had a greater effect on the increased risk for diabetes than overweight/obesity. Greater focus on metabolic health might be a more effective target for prevention and control of diabetes than emphasis on weight loss alone

    Depression in Mexican Americans with Diagnosed and Undiagnosed Diabetes

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    Background: Depression and diabetes commonly co-occur; however, the strength of the physiological effects of diabetes as mediating factors towards depression is uncertain. Method: We analyzed extensive clinical, epidemiological and laboratory data from n = 2081 Mexican Americans aged 35-64 years, recruited from the community as part of the Cameron County Hispanic Cohort (CCHC) divided into three groups: Diagnosed (self-reported) diabetes (DD, n = 335), Undiagnosed diabetes (UD, n = 227) and No diabetes (ND, n = 1519). UD participants denied being diagnosed with diabetes, but on testing met the 2010 American Diabetes Association and World Health Organization definitions of diabetes. Depression was measured using the Center for Epidemiological Studies - Depression (CES-D) scale. Weighted data were analyzed using dimensional and categorical outcomes using univariate and multivariate models. Results: The DD group had significantly higher CES-D scores than both the ND and UD (p ⩽ 0.001) groups, whereas the ND and UD groups did not significantly differ from each other. The DD subjects were more likely to meet the CES-D cut-off score for depression compared to both the ND and UD groups (p = 0.001), respectively. The UD group was also less likely to meet the cut-off score for depression than the ND group (p = 0.003). Our main findings remained significant in models that controlled for socio-demographic and clinical confounders. Conclusions: Meeting clinical criteria for diabetes was not sufficient for increased depressive symptoms. Our findings suggest that the \u27knowing that one is ill\u27 is associated with depressive symptoms in diabetic subjects

    Cardiovascular disease risk among the Mexican American population in the Texas-Mexico border region, by age and length of residence in United States

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    Introduction: Although the relationship between health behaviors and outcomes such as smoking and obesity with longer residence in the United States among Mexican American immigrants is established, the relationship between length of residency in the United States and risk for cardiovascular disease (CVD) is not fully understood. The objective of this study was to determine the relationship between immigrant status, length of residence in the United States, age, and CVD markers in a sample of Mexican American adults living in Brownsville, Texas. Methods: We categorized participants in the Cameron County Hispanic Cohort study as immigrants in the United States for 10 years or less, immigrants in the United States for more than 10 years, or born in the United States. We conducted logistic and ordinary least squares regression for self-reported chronic conditions and CVD biomarkers. Results: We found bivariate differences in the prevalence of self-reported conditions and 1 CVD biomarker (low-density lipoprotein cholesterol) by length of residence in the middle (41-64 y) and younger (18-40 y) age groups. After adjusting for covariates, the following varied significantly by immigrant status: stroke and high cholesterol (self-reported conditions) and diastolic blood pressure, systolic blood pressure, total cholesterol, and low-density lipoprotein cholesterol (CVD biomarkers). Conclusion: The association between immigrant status, length of residence in the United States, and CVD markers varied. The effect of length of residence in the United States or immigrant status may depend on age and may be most influential in middle or older age
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