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At least 397 records · Page 22Linked to original sources
PubMed2001

Topography-driven excimer laser for the retreatment of decentralized myopic photorefractive keratectomy.

OBJECTIVE: This study evaluated the efficacy, predictability, stability, and safety of a software program (Corneal Interactive Programmed Topographic Ablation, CIPTA, LIGI, Taranto, Italy), which, by transferring programmed ablation from the corneal topograph to a flying-spot excimer laser, provides customized laser ablation for correction of postmyopic photorefractive keratectomy (PRK) decentrations. DESIGN: Noncomparative consecutive case series. PARTICIPANTS: Thirty-two eyes of 32 subjects with a mean age of 35 years (range, 19-49; standard deviation [SD], 7.9) had CIPTA-guided PRK at the Clinica Oculistica of Bari University (Italy). All the subjects had irregular astigmatism after postmyopic PRK because of clinically significant, decentered treatments of more than 1 mm. OPERATION: Individual topographies were acquired by a corneal topograph (Orbscan II, Orbtek, Inc., Salt Lake City, UT). These, together with refractive data, were processed to obtain a customized altimetric ablation profile that was transferred to a flying-spot laser (Laserscan 2000, Lasersight, Orlando, FL). MAIN OUTCOME MEASURES: The topographic study of centration and data on uncorrected (UCVA) and best-corrected (BCVA) visual acuity, predictability, and stability of refraction, and any complications, were analyzed. RESULTS: Mean follow-up was 10.3 months (range, 4-18 months; SD, 5.8). At the last postoperative examination, 29 eyes (90.6%) had a UCVA superior to 20/40. Nineteen eyes (59.4%) had a UCVA of 20/20. Twenty-two eyes (68.75%) were within 0.50 diopters (D) of attempted correction in the spherical equivalent and 28 eyes (87.5%) were within 1 D. The index of success of astigmatic correction was 0.15. No eye lost Snellen lines of BCVA, whereas 18 eyes (56.25%) gained Snellen lines. Postoperative topographies revealed well-centered treatments. CONCLUSIONS: The combination of topographic data with computer controlled flying-spot excimer laser ablation is a suitable solution for correcting irregular astigmatism after postmyopic PRK decentrations.

Adult↗
PubMed2001

Corneal interactive programmed topographic ablation customized photorefractive keratectomy for correction of postkeratoplasty astigmatism.

OBJECTIVE: This study evaluated the efficacy, predictability, stability, and safety of a software program (Corneal Interactive Programmed Topographic Ablation [CIPTA], LIGI, Taranto, Italy), which, by transferring programmed ablation from the corneal topograph to a flying-spot excimer laser, provides customized laser ablation for correction of postkeratoplasty astigmatism. DESIGN: Noncomparative consecutive interventional case series. PARTICIPANTS: Ten eyes of 10 patients with a mean age of 41.4 years (range, 26-64) had CIPTA-guided photoastigmatic refractive keratectomy (PARK) at the Clinica Oculistica of Bari (Italy). Two patients were treated for hyperopic astigmatism and eight for myopic astigmatism. All the patients had irregular astigmatism after penetrating keratoplasty. OPERATION: Topography was acquired by a corneal topograph (Orbscan II, Orbtek, Inc., Salt Lake City, UT). This, together with refractive data, was processed to obtain a customized altimetric ablation profile that was transferred to a flying-spot laser (Laserscan 2000, Lasersight, Orlando, FL). MAIN OUTCOME MEASURES: Data on uncorrected (UCVA) and best-corrected (BCVA) visual acuity, predictability, stability of refraction, and any complications were analyzed. RESULTS: Mean follow-up was 8.4 months (range, 6-12; SD 2.4). At the last postoperative examination, seven eyes (70%) had a UCVA superior to 20/40. Three eyes (30%) had a UCVA of 20/20. Five eyes (50%) were within 0.50 diopters (D) of attempted correction in the spherical equivalent, and eight eyes (80%) within 1 D. Index of success of astigmatic correction was 0.19. All the eyes (100%) gained Snellen lines of BCVA. We did not observe any decentration and/or haze after PARK treatment performed in this study. CONCLUSIONS: The combination of topographic data with computer-controlled flying-spot excimer laser ablation is a suitable solution for correcting irregular astigmatism after penetrating keratoplasty.

Adult↗
PubMed2003

Diving behaviour, dive cycles and aerobic dive limit in the platypus Ornithorhynchus anatinus.

We investigated the diving behaviour, the time allocation of the dive cycle and the behavioural aerobic dive limit (ADL) of platypuses (Ornithorhynchus anatinus) living at a sub-alpine Tasmanian lake. Individual platypuses were equipped with combined data logger-transmitter packages measuring dive depth. Mean dive duration was 31.3 s with 72% of all dives lasting between 18 and 40 s. Mean surface duration was 10.1 s. Mean dive depth was 1.28 m with a maximum of 8.77 m. Platypuses performed up to 1600 dives per foraging trip with a mean of 75 dives per hour. ADL was estimated by consideration of post-dive surface intervals vs. dive durations. Only 15% of all dives were found to exceed the estimated ADL of 40 s, indicating mainly aerobic diving in the species. Foraging platypuses followed a model of optimised recovery time, the optimal breathing theory. Total bottom duration or total foraging duration per day is proposed as a useful indicator of foraging efficiency and hence habitat quality in the species.

Animals↗
PubMed2005

Abiotic production of methylmercury by solar radiation.

Methylmercury [MeHg(I) in the aerobic surface water of lakes is thought to be rapidly degraded, but contrary to expectations, we show that MeHg(I) concentrations often increase during sunlight hours or remain relatively constant. We hypothesized that there were water column processes that generated MeHg(I) and that these processes were linked to dissolved organic matter (DOM) and solar radiation. A 2-day diurnal pattern of MeHg(I) in surface water with corresponding bottled controls was assessed for two contrasting lakes in Kejimikujik, Nova Scotia, Canada. Following this study, a tangential ultrafiltrator was used to size-fractionate and generate a concentration gradient of DOM from four different lakes located near Lac Berthelot, Quebec, Canada. The watersheds of two of these lakes were not substantially logged whereas the other two had been extensively logged. Different size fractions of DOM as well as different concentrations of DOM were exposed to sunlight for varying periods of time. We observed that, in Keiimikujik, the concentration of MeHg(I) in surface waters peaked in the early afternoon. Furthermore, this also occurred in bottled water for one of the lakes, Puzzle, eliminating the possibility that in-lake mixing played a role in this pattern. The formation of MeHg(I) was found to be dependent on the size fraction and amount of DOM present in the water. Specifically, DOM less than 5 kDa or between 30 and 300 kDa generated MeHg(I) when exposed to sunlight, but larger fractions did not. Furthermore, although data are limited, we found that water from lakes with logged watersheds generated MeHg(I) when exposed to sunlight, whereas water from lakes with low levels of logging in the undisturbed watersheds did not. Our results demonstrate that MeHg(I) can be formed in freshwaters of certain lakes in response to solar radiation. This photoproduction of MeHg(I) is dependent on DOM concentrations and type, with the importance of water chemistry not yet clear. The significance of this process to freshwater lakes and the mechanism responsible for MeHg(I) photoproduction is still unclear, but a correction in the conventional wisdom that MeHg(I) is rapidly photodegraded is timely.

Animals↗
PubMed2003

Solid-phase microextraction in the analysis of virgin olive oil volatile fraction: characterization of virgin olive oils from two distinct geographical areas of northern Italy.

SPME was employed to characterize the volatile profile of virgin olive oils produced in two geographical areas of northern Italy: the region of the Gulf of Trieste and the area near Lake Garda. There are as yet no data on the headspace composition of virgin olive oils from these regions, characterized by particular conditions of growth for Olea europaea. Using the SPME technique coupled to GC-MS and GC-FID, the volatile components of 42 industrially produced virgin olive oil samples were identified and the principal compounds quantitatively analyzed. Significant differences in the proportion of volatile constituents from oils of different varieties and geographical origins were detected. The results suggest that besides the genetic factor, environmental conditions influence the volatile formation.

Chromatography, Gas↗
PubMed2003

Mixotrophs combine resource use to outcompete specialists: implications for aquatic food webs.

The majority of organisms can be grouped into those relying solely on photosynthesis (phototrophy) or those relying solely on the assimilation of organic substances (heterotrophy) to meet their requirements for energy and carbon. However, a special life history trait exists in which organisms combine both phototrophy and heterotrophy. Such "mixotrophy" is a widespread phenomenon in aquatic habitats and is observed in many protozoan and metazoan organisms. The strategy requires investment in both photosynthetic and heterotrophic cellular apparatus, and the benefits must outweigh these costs. In accordance with mechanistic resource competition theory, laboratory experiments revealed that pigmented mixotrophs combined light, mineral nutrients, and prey as substitutable resources. Thereby, they reduced prey abundance below the critical food concentration of competing specialist grazers [Rothhaupt, K. O. (1996) Ecology 77, 716-724]. Here, we demonstrate the important consequences of this strategy for an aquatic community. In the illuminated surface strata of a lake, mixotrophs reduced prey abundance steeply. The data suggest that, as a consequence, grazers from higher trophic levels, consuming both the mixotrophs and their prey, could not persist. Thus, the mixotrophs escaped from competition with and losses to higher grazers. Furthermore, the mixotrophs structured prey abundance along the vertical light gradient, creating low densities near the surface and a pronounced maximum of their algal prey at depth. Such deep algal accumulations are typical features of nutrient-poor aquatic habitats, previously explained by resource availability. We hypothesize instead that the mixotrophic grazing strategy is responsible for deep algal accumulations in many aquatic environments.

Animals↗
PubMed1995

Effect of outdoor airborne particulate matter on daily death counts.

To investigate the possible relationship between airborne particulate matter and mortality, we developed regression models of daily mortality counts using meteorological covariates and measures of outdoor PM10. Our analyses included data from Cook County, Illinois, and Salt Lake County, Utah. We found no evidence that particulate matter < or = 10 microns (PM10) contributes to excess mortality in Salt Lake County, Utah. In Cook County, Illinois, we found evidence of a positive PM10 effect in spring and autumn, but not in winter and summer. We conclude that the reported effects of particulates on mortality are unconfirmed.

Air Pollutants↗
PubMed2004

[The co-occurence of Cryptosporidium parvum, Giardia spp. and helminth infections in small rodent populations].

During long-term (1998-2000) studies on rodent parasite populations in Mazury lake district there were collected and analyzed data on co-occurrence of intestinal protozoa (Cryptosporidium parvum, Giardia spp.) and helminths. There were performed 178 autopsies of common vole Microtus arvalis, 85 autopsies of yellow-necked mouse Apodemus flavicollis and 386 autopsies of bank vole Clethrionomys glareolus. Positive effect of helminth infections was found in C. glareolus. Voles infected with nematode Heligmosomum mixtum showed higher prevalence of C. parvum and Giardia spp. than voles infected with Heligmosomoides glareoli. The host age took part in these interactions and positive effect of co-occurrence was mainly observed in voles older than 3 months. The other intrinsic (host sex) or extrinsic (season and year of study) factors influenced interactions between parasites. Presented results revealed that helminth infections may facilitate chronic infections of intestinal protozoa in rodent populations.

Age Factors↗
PubMedDate not supplied

[Migration characteristics and forms of 90Sr and 137Cs observed in the bottom sediments of certain lacustrine ecosystems on the East Urals Radioactive Trace].

The research findings summarized in the paper include data on the radioecological conditions in two lakes (Large Ighish and Small Ighish) located on the East Urals Radioactive Trace. The focus of the study was on the chemical composition of water and bottom sediments, as well as on the specific features of 90Sr and of 137Cs distribution and the forms in which they occur in silts. Coefficients of radionuclide accumulation in the bottom deposits of the lakes of interest were estimated. A conclusion was drawn about the dependences influencing radionuclide distribution by layers of the lake bottom sediments.

Cesium Radioisotopes↗
PubMed1984

Xenobiotics in gametes of Lake Michigan lake trout (Salvelinus namaycush) induce hepatic monooxygenase activity in their offspring.

Eggs spawned from Lake Michigan lake trout contain a number of xenobiotic compounds, including polychlorinated biphenyls (PCBs). To assess whether this contamination is sufficient to induce hepatic cytochrome P-450-dependent monooxygenase (MO) activity during early development, the hepatic MO systems of laboratory-cultured offspring of Lake Michigan, Green Bay, and Marquette Hatchery lake trout were compared. Additionally, the induction of hepatic cytochrome P-450 systems in developing lake trout by the commercial PCB mixture, Aroclor 1254 (A1254), was characterized. During late embryonic development and at the swim-up stage, the hepatic MO systems of the feral lake trout offspring appeared induced, based on levels of aryl hydrocarbon hydroxylase (AHH) activity that were 3.5- to 8.6-fold higher than the hatchery control levels. Furthermore, at the swim-up stage the feral trout offspring resembled A1254-treated hatchery fry with regard to the degree of inhibition of hepatic AHH activity by alpha-naphthoflavone, and the presence of an inducible Mr = 58,000 polypeptide in hepatic microsomes. The levels of aminopyrine N-demethylase activity, which was relatively unresponsive to inducers, were moderately lower in the Lake Michigan and Green Bay swim-up fry compared to the hatchery control levels. After 7 months of posthatching laboratory culture, when residues of xenobiotics present at fertilization were greatly diluted by growth, the hepatic MO systems of the Lake Michigan and hatchery trout offspring appeared essentially indistinguishable with regard to a number of parameters. These results indicate that the differences observed between the hatchery and feral trout offspring at earlier stages were not likely to have a genetic basis, but rather were due to a xenobiotic-type induction. Dose-response experiments and residue analysis data indicated that residues of commercial PCB mixtures were at least partially responsible for the effects described here. Overall, these data provide very strong evidence that contamination of Lake Michigan lake trout gametes by PCBs and possibly other xenobiotics caused induction of hepatic MO activity in their progeny. Fish embryos and fry with induced MO systems may have an increased sensitivity to the toxicity of certain environmental contaminants that are metabolically activated by cytochrome P-450.

Animals↗
PubMed1996

Blood gas analysis of placental and uterine blood during cesarean delivery.

OBJECTIVE: To measure blood gases in uterine venous blood and maternal and fetal blood from the placenta, and to characterize gas exchange in the intervillous space. METHODS: Blood gas measurements were performed immediately after collecting placental and uterine blood from the subchorial and marginal lakes, from the chorionic vein and artery in the placenta in utero, and from the uterine vein during 12 cesarean deliveries. RESULTS: The mean oxygen pressure (PO2) values of the chorionic vein and subchorial lake were 28.7 +/- 6.0 and 29.9 +/- 7.5 mmHg, respectively, with a difference of 1.2 mmHg. The individual data for PO2 of the chorionic vein exceeded those of the subchorial lake in five subjects and were almost equal in two of the 12 subjects. The mean values of carbon dioxide pressure (PCO2) and bicarbonate were greater in the chorionic vein than in the subchorial lake, but the mean pH values were the same in the two groups. The mean values of blood gas analysis were not different between subchorial and marginal lakes with similar blood composition. The mean PO2 of the uterine vein in ten subjects was 45.9 mmHg, significantly higher than that of the subchorial lake. CONCLUSIONS: The human placenta may be defined as a multivillous model with a high degree of oxygen transfer. Arteriovenous anastomoses are suspected in the pregnant uterus beyond 37 weeks' gestation. Subchorial and marginal lakes contain similar admixed blood, which circulates and performs gas exchange.

Blood Gas Analysis↗
PubMed1996

Survey of microcystins in environmental water by a highly sensitive immunoassay based on monoclonal antibody.

By using a highly sensitive enzyme-linked immunosorbent assay (ELISA) based on a monoclonal antibody, microcystin (MC) concentration was analyzed in environmental water samples (total, 134), collected in 1993-1995 from ponds, lakes, reservoirs, and rivers in Japan, Thailand, Germany, and Portugal. MCs detected in the water samples filtered over a glass filter were designated as free MCs, and those samples that were freeze-thawed twice before the filtration were designated as total MCs. MCs (> 50 pg/ml) were detected in 14 of 24 samples collected from the lakes that were used as recreation and water supply in Japan in different regions. In the MC-positive samples, the concentration of free MCs was only a few percentages of the total MCs, indicating that the most part of MCs found in the water samples was present in algal cells. An additional trial on 33 samples collected continuously from Lake Inbanuma, Japan, during June-September 1994-1995 revealed that the total MCs were in a range of 52-52,000 pg/ml. In Chiang Mai, Thailand, 6 of 10 samples were positive, with the mean and highest of 161 and 354 pg/ml, respectively. In the Frankfurt area. Germany, 4 of 10 and 7 of 8 samples collected in the same lakes for recreation in July 1993 and November-December 1994 showed the presence of MCs, with their mean and highest values of 257 and 407 pg/ml, respectively. Another survey of MCs in dense bloomed samples collected with plankton net revealed a contamination of MCs up to 36,000 pg/ml. In Portugal, 28 of 29 samples from 4 lakes, 20 rivers, and 5 reservoirs were positive for MCs, with the respective means of 13,664, 11,048, and 2,278 pg/ml. These data indicated that MCs contaminate environmental water in ponds, rivers, lakes, and reservoirs worldwide. The present ELISA is considered to be a reliable tool for the mass monitoring and risk assessment of MCs in water supplies.

Antibodies, Monoclonal↗
PubMedDate not supplied

Maternal consumption of Lake Ontario salmon in rats produces behavioral changes in the offspring.

The current study assessed the effects of maternal, paternal, or combined parental consumption of Lake Ontario salmon in rats on the behavior of their offspring. Adult female Sprague-Dawley rats were put on a 30 day diet of either ground rat chow containing 30% Lake Ontario salmon (LAKE) or 30% Pacific Ocean salmon (OCEAN). These females were then mated with adult male rats similarly exposed (LAKE or OCEAN). An additional control group of males and females who were fed ground rat chow (MASH) only were also mated. These pairing combinations resulted in five offspring groups: LAKE-LAKE, LAKE-OCEAN, OCEAN-LAKE, OCEAN-OCEAN, MASH-MASH. When the offspring reached 80 days of age, they were tested for reactivity to frustrative nonreward using runway successive negative contrast, which has been repeatedly shown to be increased in adult rats fed Ontario salmon. Consistent with previous work, results showed that the behavior of the OCEAN-OCEAN rats did not differ from the MASH-MASH group, indicating that a salmon diet per se does not cause behavioral change. However, the offspring of dams who consumed Lake Ontario salmon (LAKE-LAKE and OCEAN-LAKE) showed an increased depression effect relative to controls. There was little evidence of a paternal effect. A follow-up experiment employed cross-fostering to determine the relative contribution of pre- and/or postnatal exposure to Lake Ontario salmon consumption on offspring behavior. Rat pups were cross-fostered to or from dams who consumed Lake Ontario salmon during gestation and parturition. Results from two separate replications indicated that prenatal (LAKE to OCEAN) exposure alone or postnatal (OCEAN to LAKE) exposure alone produced a large increase in successive negative contrast relative to controls (OCEAN to OCEAN). These data are strong evidence of behavioral changes produced by maternal consumption of Lake Ontario salmon in the offspring rat. Further, they indicate that either prenatal or postnatal exposure alone is sufficient to produce behavioral changes in the offspring.

Animals↗
PubMed2005

Comparative phylogenetic analyses of the adaptive radiation of Lake Tanganyika cichlid fish: nuclear sequences are less homoplasious but also less informative than mitochondrial DNA.

Over 200 described endemic species make up the adaptive radiation of cichlids in Lake Tanganyika. This species assemblage has been viewed as both an evolutionary reservoir of old cichlid lineages and an evolutionary hotspot from which the modern cichlid lineages arose, seeding the adaptive radiations in Lakes Victoria and Malawi. Here we report on a phylogenetic analysis of Lake Tanganyika cichlids combining the previously determined sequences of the mitochondrial ND2 gene (1047 bp) with newly derived sequences of the nuclear RAG1 gene (approximately 700 bp of intron 2 and approximately 1100 bp of exon 3). The nuclear data-in agreement with mitochondrial DNA-suggest that Lake Tanganyika harbors several ancient lineages that did not undergo rampant speciation (e.g., Bathybatini, Trematocarini). We find strong support for the monophyly of the most species-rich Tanganyikan group, the Lamprologini, and we propose a new taxonomic group that we term the C-lineage. The Haplochromini and Tropheini both have an 11-bp deletion in the intron of RAG1, strongly supporting the monophyly of this clade and its derived position. Mapping the phylogenetically informative positions revealed that, for certain branches, there are six times fewer apomorphies in RAG1. However, the consistency index of these positions is higher compared to the mitochondrial ND2 gene. Nuclear data therefore provide, on a per-base pair basis, less but more reliable phylogenetic information. Even if in our case RAG1 has not provided as much phylogenetic information as we expected, we suggest that this marker might be useful in the resolution of the phylogeny of older groups.

Animals↗
PubMed2002

Elaboration of a complex GIS application in a catchment area.

Rearrangement of land resources after political changes has not yet been finished in Hungary. It is almost impossible to collect information necessary for planning activities on outer areas of settlements. The data are distributed among various organizations and can be found in diverse forms or there are no available data at all. However water quality protection has become legally ordered concerning municipal activities around Lake Balaton which is considered as the most important recreation area and tourist target in Hungary and is also affected by a number of factors providing sources of environmental conflicts. Settlements in a catchment area (Tetves Creek) on the southern shoreline of Lake Balaton in Central Hungary tendered a complex project for collecting sources of authentic data of the Hungarian rural areas along with systematizing and saving these data in a uniform GIS. An application using Autodesk MapGuide Program for Internet realization was developed. The implemented web-based system can be used in Internet and Intranet environments.

Automation↗
PubMed2000

Planning for an annual episodic mass gathering: emergency department and clinic utilization in Yellowstone.

OBJECTIVE: Planning and providing emergency and primary care for a large transient population of visitors and employees in a national park can be problematic. Furthermore, planning for emergency and primary health care needs of visitors and itinerant workers in a wilderness area national park has not been well documented. A study was performed to analyze emergency and primary health care utilization in a national park. METHODS: Data was gathered from all patients presenting to Lake Hospital Emergency Department in Yellowstone in 1995, and a retrospective chart review was performed. RESULTS: Two distinct populations with different health care needs were identified. CONCLUSION: Utilization analysis revealed differences between conventional mass gatherings and the mass gatherings in Yellowstone. Because of the unique conditions and populations found in a wilderness area, conventional mass gathering emergency medical service models may not be an appropriate model for planning health care in a national park. Analysis of utilization data can help plan resources for emergency and primary health care for a park population.

Adolescent↗
PubMed1996

Helminth infections, morbidity indicators and schistosomiasis treatment history in three villages, Dongting Lake region, PR China.

In order to estimate the public health impact of helminth infections, and to provide baseline data for interventions, parasitological and morbidity surveys were conducted among inhabitants of three villages in Dongting Lake region, Hunan Province, China. Ascaris lumbricoides was found to be the most common helminth infection, followed by Trichuris trichiura and Schistosoma japonicum. Left liver enlargement was the most common indicator of morbidity. Observed numbers of multiple species infections closely correlated with expected figures generated from a simple probabilistic model. Heterogeneity was observed in age and sex-standardized infection and morbidity prevalences among the villages and occupations. Males had higher levels of infection, were more likely to suffer morbidity, and were more likely to have been treated for schistosomiasis than women. The prevalence of each morbidity indicator was positively correlated with the number of times of treatment for schistosomiasis, and negatively correlated with number of years since last treatment. The results imply that treatment history for S. japonicum infection may be a good indicator of current morbidity risk.

Adolescent↗
PubMed1989

Caesium-137 in Perch in Swedish Lakes after Chernobyl-present situation, relationships and trends.

The Chernobyl accident, and the general acidification of Swedish water systems, form the base for this project. The aims of the work have been to present results on the linkage between the concentration of Cs-137 in fish, lake load of Cs and lake characteristics, to give a preliminary prognosis on the recovery, and to put the results within a wider framework of environmental hazard analysis. A broad set of data on limnology, morphometry and drainage area conditions from 41 lakes were collected during 1986 and 1987. Cs-137 was determined in 1 + perch (Cs-pe, 1-year-old perch), water, material collected by sediment traps and from surficial sediments. The main results are as follows. The average value of Cs-pe for all lakes has dropped from 9800 Bq kg(-1) (wet) to 5040 between the 2 years. Generally, the decrease is between 5 and 90%. We have tested if any factor(s) could be specifically linked to this decrease-no such factors have been found. The concentrations of Cs in sediment traps have, on average, decreased by 80%. Very high correlations exist between Cs-pe and the caesium load as determined from the sediment traps. Between 1 and 10% (mean 3.9%) of the initial fall-out deposition to the drainage area was transported from land to water during June to August 1986. The variation in initial fall-out deposition explains 65-69% of the variability in Cs-pe; the degree of explanation (= coefficient of determination, r2) increases to about 85% if one also takes into account the lake water hardness and totP. A map showing with lakes likely to have 1 + perch with higher mean Cs-concentrations than 1500 Bq kg(-1) wet is presented. Between 4000 and 7000 lakes in Sweden appear to have Cs-pe higher than 1500 Bq kg(-1) wet, figures which emphasize the serious impact of the Chernobyl accident on the environmental conditions in Sweden.

Journal Article↗