Summit-to-sea mapping and change detection using satellite imagery: tools for conservation and management of coral reefs

Continuous summit-to-sea maps showing both land features and shallow-water coral reefs have been completed in Puerto Rico and the U.S. Virgin Islands, using circa 2000 Landsat 7 Enhanced Thematic Mapper (ETM+) Imagery. Continuous land/sea terrain was mapped by merging Digital Elevation Models (DEM) with satellite-derived bathymetry. Benthic habitat characterizations were created by unsupervised classifications of Landsat imagery clustered using field data, and produced maps with an estimated overall accuracy of>75% (Tau coefficient >0.65). These were merged with Geocover-LC (land use/land cover) data to create continuous land/ sea cover maps. Image pairs from different dates were analyzed using Principle Components Analysis (PCA) in order to detect areas of change in the marine environment over two different time intervals: 2000 to 2001, and 1991 to 2003. This activity demonstrates the capabilities of Landsat imagery to produce continuous summit-to-sea maps, as well as detect certain changes in the shallow-water marine environment, providing a valuable tool for efficient coastal zone monitoring and effective management and conservation

Summit-to-sea mapping and change detection using satellite imagery: tools for conservation and management of coral reefs.

Continuous summit-to-sea maps showing both land features and shallow-water coral reefs have been completed in Puerto Rico and the U.S. Virgin Islands, using circa 2000 Landsat 7 Enhanced Thematic Mapper (ETM+) Imagery. Continuous land/sea terrain was mapped by merging Digital Elevation Models (DEM) with satellite-derived bathymetry. Benthic habitat characterizations were created by unsupervised classifications of Landsat imagery clustered using field data, and produced maps with an estimated overall accuracy of>75% (Tau coefficient >0.65). These were merged with Geocover-LC (land use/land cover) data to create continuous land/ sea cover maps. Image pairs from different dates were analyzed using Principle Components Analysis (PCA) in order to detect areas of change in the marine environment over two different time intervals: 2000 to 2001, and 1991 to 2003. This activity demonstrates the capabilities of Landsat imagery to produce continuous summit-to-sea maps, as well as detect certain changes in the shallow-water marine environment, providing a valuable tool for efficient coastal zone monitoring and effective management and conservation.

Monitoring dietary change in a low-fat diet intervention study: advantages of using 24-hour dietary recalls vs food records.

OBJECTIVE: The purpose of the study was to evaluate two methods of dietary assessment for monitoring change in fat intake in a low-fat diet intervention study. DESIGN: The two dietary assessment methods were a 4-day food record (4DFR) and an unannounced 24-hour dietary recall conducted by telephone interview (referred to as a telephone recall [TR]). Subjects were assigned randomly to either a low-fat diet intervention group or a control group that received no counseling about fat intake. Dietary data were collected at baseline, 6 months, and 12 months. SUBJECTS: Two hundred ninety postmenopausal women with localized breast cancer were recruited at seven clinical centers in the United States. STATISTICAL ANALYSIS: Analysis of variance was used to test for significant differences in mean fat and energy intakes. RESULTS: Three sources of error were identified: (a) an instrument effect, suggesting underreporting at baseline of approximately 8% in mean energy intake and 11% in mean fat intake in the TR group compared with the 4DFR group (P = .0001); (b) a repeated measures effect observed for the 4DFR, suggesting underreporting of approximately 7% for energy intake and 14% for fat intake in the control group at 6 and 12 months compared with baseline values (P < .001); and (c) an adherence effect (or compliance bias), suggesting greater compliance to the low-fat intervention diet when subjects were keeping food records than when estimates were based on the unannounced TR. Compared with the TR, the 4DFR overestimated the extent of fat reduction in the low-fat diet intervention group by 41% (P = .08) and 25% (P = .62) at 6 and 12 months, respectively. APPLICATION: Multiple days of unannounced 24-hour recalls may be preferable to multiple-day food records for monitoring dietary change in diet intervention studies.

Eicosanoids derived from arachidonic and eicosapentaenoic acids inhibit T cell proliferative response.

Eicosanoids derived from arachidonic acid (PGE2 and LTB4) have been shown to be involved in the control of mitogen-induced proliferation of lymphocytes but the effects of (n-3) polyunsaturated fatty acids (PUFA)-derived eicosanoids (PGE3 and LTB5) on mitogenic response have not been well described. Supplementation with (n-3) PUFA decreases lymphocyte proliferation in human and animal models. The present study was designed to compare the effect of (n-3)- and (n-6)-derived eicosanoids on mitogenic response. Mouse splenocytes and human peripheral blood mononuclear cells (PBMC) were cultured in the presence or absence of the T cell mitogen Concanavalin A (CON A) with and without the addition of PGE2, LTB4, PGE3 and LTB5 at several concentrations. Lymphocyte proliferation was determined by measuring incorporation of [3H]thymidine into newly synthesized DNA. Both (n-3) and (n-6)-derived eicosanoids inhibited T cell mitogen-induced lymphocyte proliferation in human PBMC and murine splenocytes. The addition of PGE3 and LTB5 decreased Con A-induced mitogenic response in human PBMC more than the same concentration of PGE2 and LTB4 (e.g. -28.7 +/- 4.2% with 10(-9) M PGE3 vs -9.4 +/- 6.3% with 10(-9) M PGE2, P = 0.05 and -95.5 +/- 1.6% with 10(-11) M LTB5 vs -49.2 +/- 3.8% with 10(-11) M LTB4, p < 0.001). A similar trend was observed in murine splenocytes. It is concluded that PGE3 and LTB5 are as potent and at some doses more potent than PGE2 and LTB4 in inhibiting lymphocyte proliferation when added in vitro. These data suggest that eicosanoids derived from (n-3) PUFA may contribute to the (n-3) PUFA-induced suppression of lymphocyte proliferation.

Lung eicosanoid synthesis is affected by age, dietary fat and vitamin E.

The effect of age, dietary fat type and all-rac-alpha-tocopheryl acetate (vitamin E) supplementation on ex vivo synthesis of lung eicosanoids was measured in C57BL/6NIA mice using a 2 (age) x 3 (fat) x 3 (vitamin E) factorial design. Young (3-mo-old) and old (24-mo-old) mice were fed a semipurified diet containing 5% (by wt) corn oil, coconut oil or fish oil supplemented with 30, 100 or 500 mg vitamin E/kg for 4 wk. Ex vivo synthesis of thromboxane B2 (TXB2) and 6-keto-prostaglandin F1 alpha (PGI2) were measured by RIA in lung homogenates. Old mice had significantly higher concentrations of TXB2 and PGI2 than did young mice, resulting in a significant increase in the TXB2:PGI2 ratio with aging. Young and old mice fed fish oil had significantly lower concentrations of PGI2 and TXB2 than those fed corn oil or coconut oil. The degree of reduction varied according to age and vitamin E status. Old mice fed fish oil and 30 mg vitamin E/kg diet had the lowest plasma vitamin E concentration and the highest TXB2:PGI2 ratio. The TXB2:PGI2 ratio was significantly reduced in old mice fed coconut oil or fish oil by vitamin E supplementation. Vitamin E supplementation (100 mg/kg) significantly increased PGI2 concentration in young mice fed coconut oil. Thus, significant changes in the capacity of lung to synthesize eicosanoids occur with age and are influenced by dietary fat type and vitamin E. J. Nutr.

Estimating energy requirements for children with renal disease: a comparison of methods.

The resting energy expenditure of children with renal disease is unknown. We assessed resting energy expenditure using indirect calorimetry in a group of 16 children aged 3.6 to 15.7 years (mean +/- standard deviation = 9.4 +/- 4.6 years) with renal disease and compared these results with standard prediction formulas. Measured resting energy expenditure was compared with norms predicted from the Mayo Clinic standards for children 6 years of age and older, the combined data reported by Passmore, and the most recent equations provided by the Food and Agriculture Organization/World Health Organization/United Nations University (FAO/WHO/UNU). The Mayo Clinic standards overpredicted resting energy expenditure in 7 of 10 subjects, whereas the Passmore standards and the FAO/WHO standards underpredicted resting energy expenditure in 10 of 16 and 9 of 16 subjects, respectively. When adjusted for the age of the subject, our findings indicate that all three standards are useful for predicting resting energy expenditure in children 6 years and older with renal disease, but no current standard adequately predicts the resting energy expenditure of children less than 6 years of age with renal disease.

Influence of dietary fat, vitamin E, ethoxyquin and indomethacin on the synthesis of prostaglandin E2 in brain regions of mice.

The regional brain synthesis of prostaglandin E2 (PGE2) of rats varies with age and dietary vitamin E. We investigated ex-vivo synthesis of PGE2 in brain regions of 24-mo-old male C57BL/6Nia mice. Mice were fed semipurified diets containing 1) 5% by weight of vitamin E-stripped corn oil, nonhydrogenated coconut oil or fish oil, or 2) 3.8% lard + 1.2% stripped corn oil (control), each supplemented with 30 or 500 mg of vitamin E per kg for 6 wk. In addition, two groups of mice were fed control diets containing 2500 mg of ethoxyquin/kg or 1 mg of indomethacin/(kg.day). Mice fed fish oil had lower (P less than 0.01) plasma alpha-tocopherol than those fed coconut oil. Vitamin E supplementation had no effect on the concentration of alpha-tocopherol in most brain regions. The rank order of PGE2 synthesis among all groups was cerebrum = cerebellum greater than midbrain greater than brainstem. Vitamin E supplementation tended to reduce brain PGE2 synthesis. Fat with 30 mg/kg of vitamin E in their diet. In the brainstem, fish oil significantly reduced PGE2 relative to mice fed corn oil. Ethoxyquin lowered plasma alpha-tocopherol by 42% and reduced the PGE2 synthesis in brain regions, and indomethacin reduced it by 50%. Thus, ethoxyquin and indomethacin significantly reduced the brain's regional capacity for PGE2 synthesis, whereas vitamin E was not effective for the period tested. The reduction of PGE2 synthesis in the brain with fish oil feeding in this study was not as notable as reported for other tissues unless combined with high-dose vitamin E supplementation.

Volume status and body composition of chronic dialysis patients: utility of bioelectric impedance plethysmography.

We assessed the utility of bioelectric impedance plethysmography (BIA) for measuring acute volume changes and body composition in patients with renal disease. Chronic hemodialysis and peritoneal dialysis patients were evaluated before and after dialysis. Total body water, as measured by BIA, predicts body weight. Acute changes in body water, induced by dialysis, are not predicted well by data derived from BIA. Body fat (%) and fat-free mass (%), determined by anthropometry, are predicted well by body composition data derived by BIA. BIA is useful for assessing body composition in this population, but must be cautiously applied to the measurement of acute volume changes.

Effect of age and dietary fat (fish, corn and coconut oils) on tocopherol status of C57BL/6Nia mice.

The effect of age and dietary fat type on tocopherol status was investigated using young and old C57BL/6Nia mice fed semipurified diets containing 5% (by weight) fish, corn or coconut oils and supplemented with 30, 100 or 500 ppm dl-alpha-tocopheryl acetate for 6 wk. Tocopherol levels in the diets, plasma, liver, kidney and lung were measured by high performance liquid chromatography following appropriate extractions. The results indicate that mice fed fish oil maintain lower plasma and tissue tocopherol concentrations than those fed corn and coconut oils (fish less than corn oil less than coconut oil). The difference was not due to a loss of tocopherol prior to consumption, but rather appeared to occur during the absorption process. Old mice had lower plasma and liver tocopherol concentrations than young mice. Old mice fed fish oil, however, maintained plasma tocopherol levels better than young mice fed fish oil, presumably due to their larger tocopherol pool. No age effect was detected on kidney and lung tocopherol levels. It is concluded that tocopherol status is affected by age and dietary fat type, especially fish oil.