960 resultados para Ecology--Ontario, Lake (N.Y. and Ont.)


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In order to detect fluctuations in ruminal microbial populations due to forage tannins using 16S ribosomal RNA (rRNA) probes, recovery of intact rRNA is required. The objective of this work was to evaluate the effect of polyethylene glycol (PEG) and polyvinylpirrolidone (PVP) on extraction of bacterial rRNA, in the presence of tannins from tropical legume forages and other sources, that hybridize with oligonucleotide probes. Ruminococcus albus 8 cells were exposed to 8 g/L tannic acid or 1 g/L condensed tannins extracted from Acacia angustissima, banana (Musa sp.) skin, Desmodium ovalifolium, red grape (Vitis vinifera) skin and Inga edulis, or no tannins. Cells were rinsed with Tris buffer pH 7 containing either 8% PEG or 6% PVP prior to cell lysis. Total RNA samples rinsed with either PEG or PVP migrated through denaturing agarose gels. The 16S rRNA bands successfully hybridized with a R. albus species-specific oligonucleotide probe, regardless of tannin source. The effect of rinsing buffers on the density of 16S rRNA bands, as well as on the hybridization signals was compared. There were significant effects (P<0.01) when the controls were compared to either buffer treatments due to tannin type, buffer used and the interaction of tannin type and buffer. The significant interaction indicates the influence of tannin type on the parameters evaluated.

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Peroxisome proliferator-activated receptor alpha (PPARalpha)is a nuclear receptor for various fatty acids, eicosanoids, and hypolipidemic drugs. In the presence of ligand, this transcription factor increases expression of target genes that are primarily associated with lipid homeostasis. We have previously reported PPARalpha as a nuclear receptor of the inflammatory mediator leukotriene B(4) (LTB(4)) and demonstrated an anti-inflammatory function for PPARalpha in vivo (Devchand, P. R., Keller, H., Peters, J. M., Vazquez, M., Gonzalez, F. J., and Wahli, W. (1996) Nature 384, 39-43). LTB(4) also has a cell surface receptor (BLTR) that mediates proinflammatory events, such as chemotaxis and chemokinesis (Yokomizo, T., Izumi, T., Chang, K., Takuwa, Y., and Shimizu, T. (1997) Nature 387, 620-624). In this study, we report on chemical probes that differentially modulate activity of these two LTB(4) receptors. The compounds selected were originally characterized as synthetic BLTR effectors, both agonists and antagonists. Here, we evaluate the compounds as effectors of the three PPAR isotypes (alpha, beta, and gamma) by transient transfection assays and also determine whether the compounds are ligands for these nuclear receptors by coactivator-dependent receptor ligand interaction assay, a semifunctional in vitro assay. Because the compounds are PPARalpha selective, we further analyze their potency in a biological assay for the PPARalpha-mediated activity of lipid accumulation. These chemical probes will prove invaluable in dissecting processes that involve nuclear and cell surface LTB(4) receptors and also aid in drug discovery programs.

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The objective of this work was to characterize Pantaneiro cattle genetically through its paternal ancestry by the morphology of the Y chromosome, whether submetacentric or acrocentric, as well as to identify the maternal ancestry through mitochondrial DNA. The karyotype and mitochondrial DNA of 12 bulls of Pantaneiro breed were analyzed. The Y chromosome was analyzed in lymphocyte metaphases and the mitochondrial DNA by diagnosing its haplotype (Bos taurus and Bos indicus). Among Pantaneiro animals analyzed three had a taurine (submetacentric) Y and nine had a zebuine (acrocentric) Y chromosome, suggesting breed contamination by Zebu cattle, once Pantaneiro is considered to be of European origin. The mitochondrial DNA was exclusively of taurine origin, indicating that the participation of zebuines in the formation of the breed occurred entirely through the paternal line.

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Summary of biological monitoring of Iowa's streams and rivers.

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OBJECTIVE: Body mass index does not discriminate body fat from fat-free mass or determine changes in these parameters with physical activity and aging. Body fat mass index (BFMI) and fat-free mass index (FFMI) permit comparisons of subjects with different heights. This study evaluated differences in body mass index, BFMI, and FFMI in physically active and sedentary subjects younger and older than 60 y and determined the association between physical activity, age, and body composition parameters in a healthy white population between ages 18 and 98 y. METHODS: Body fat and fat-free mass were determined in healthy white men (n = 3549) and women (n = 3184), between ages 18 and 98 y, by bioelectrical impedance analysis. BFMI and FFMI (kg/m2) were calculated. Physical activity was defined as at least 3 h/wk of endurance-type activity for at least 2 mo. RESULTS: Physically active as opposed to sedentary subjects were more likely to have a low BFMI (men: odds ratio [OR], 1.4; confidence interval [CI], 0.7-2.5; women: OR 1.9, CI 1.6-2.2) and less likely to have very high BFMI (men: OR, 0.2; CI, 0.1-0.2; women: OR, 0.1; CI, 0.02-0.2), low FFMI (men: OR, 0.5; CI, 0.3-0.9; women: OR, 0.7; CI, 0.6-0.9), or very high FFMI (men: OR, 0.6; CI, 0.4-0.8; women: OR, 0.7; CI, 0.5-1.0). Compared with subjects younger than 60 y, those older than 60 y were more like to have very high BFMI (men: OR, 6.5; CI, 4.5-9.3; women: OR, 14.0; CI, 9.6-20.5), and women 60 y and older were less likely to have a low BFMI (OR, 0.4; CI, 0.2-0.5). CONCLUSIONS: A clear association was found between low physical activity or age and height-normalized body composition parameters (BFMI and FFMI) derived from bioelectrical impedance analysis. Physically active subjects were more likely to have high or very high or low FFMI. Older subjects had higher body weights and BFMI.

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Little River Lake watershed is a 13,305 acre subwatershed of Little River. The 788 acre lake was listed as a 303d impaired water body in 2008 due to elevated turbidity and algae levels. The Decatur SWCD has prioritized water quality protection efforts within the Little River Lake watershed because 1) portions of this watershed has been identified as the primary contributor of sediment and nutrients to Little River Lake, which provides an essential source of drinking water for Decatur County and the Southern Iowa Rural Water Association; 2) the watershed provides exemplary education and project interpretation opportunities due to its proximity to Little River Lake Recreation Area, and 3) by using targeted and proven soil conservation practices to address water quality deficiencies the probability of successfully attenuating soil erosion and ameliorating water quality impairments is enhanced. The specific goals of this proposal are to: 1. reduce annual sediment, and phosphorous delivery to the lake by 11,280 tons and 14,664 lbs., respectively, via applications of conservation practices on targeted agricultural land; 2. delist the lake as an EPA 303d impaired water body via water quality enhancement; 3. obtain a “Full Support” status for the lake’s aquatic life and recreational use; 4. reduce potable water treatment costs (minimum 50% cost reduction) associated with high suspended solid levels; and 5. restore a viable sport-fish population, thereby bolstering tourism and the economy. To achieve timely project implementation the Decatur SWCD has cooperated with the IDNR Watershed Improvement Section, Fisheries Bureau, and IDALS-DSC to assess extant water quality and watershed conditions, coalesced a diverse team of committed partners and secured matching funding from multiple sources.

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Silver Lake is located in an 18,053-acre watershed. The watershed is intensively farmed with almost all of the wetlands being previously drained or degraded over the last 50 years. Silver Lake is listed on the State of Iowa’s impaired water bodies list due to sediment and high nutrient level. Silver Lake is also known be in the bottom 25 percentile of Iowa’s lakes due Secchi disk readings and Chlorophyll a level. Farming in the watershed is the principle concern and cause for many of the problems occurring in Silver Lake currently with 78% of the watershed being intensively farmed. There are two major drainage ditches that have been used to drain the major wetlands and sloughs that, at one time, filtered the water and slowed it down before it reached Silver Lake. With these two major drainage ditches, water is able to reach the lake much faster and unfiltered than it once did historically. The loss of 255 restorable wetland basins to row crop production has caused serious problems in Silver Lake. These wetland basins once slowed and filtered water as it moved through the watershed. With their loss over the last 50 years that traditional drainage no longer occurs. We propose to create a Wetland Reserve Program incentive project to make WRP a more attractive option to landowners within the watershed. The incentive will be based on the amount of sediment delivery reduction to the lake, therefore paying a greater payment for a greater benefit to the lake. The expected result of this project is the restoration of over 250 acres of wetland basins with an associated 650 acres of upland buffers. The benefit for these wetlands and buffers would be reduced sediment, reduced nutrients, and slowed waters to the lake.

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The Central Park Lake Watershed Assessment and Management Plan identified four categories where improvements are needed to remove the 23 acre lake from the impaired waters list. These include the wastewater system, runoff from surrounding lands, in-lake nutrient re-suspension and runoff from hard surfaces within the park. The lake is currently impaired for bacteria, algae and pH. Through outcomes of the Watershed Assessment and Management Plan, this proposal includes for abandonment and reclamation of the single cell wastewater lagoon site, replacement with three conventional septic systems and construction of two wetlands. One of the wetlands is located on the same site as the reclaimed lagoon and the other is located to intercept sediment and trap nutrients transported by tile lines. The prescribed wastewater system improvements are based on assessment by grab samples test by the State Hygienic Lab, development of a Preliminary Engineering Report, soil analysis and communication with IDNR wastewater officials. The two wetland sites were assessed by officials from IDALS and the Jones County SWCD. This project is part of $1.7 million lake restoration effort to reclaim the 47 year old lake. The lake has a positive economic impact of more than $7.6 million annually and supports an average annual visitation of 58,145, according to the Iowa Lakes Valuation Project, conducted by Iowa State University.

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Storm Lake, the state's fourth largest natural lake, has been the centerpiece of significant economic development, including a resort, water park, and state marina. While there have been considerable improvements to the lake's water quality through a major on-going lake restoration program and watershed project, the Little Storm Lake area still needs to be addressed. Little Storm Lake is a 190 acre area on the nmihwest side of Storm Lake. The water level in both areas is based on the dam height located on the southeast corner of Storm Lake. Approximately 70% of the water from the watershed flows through Little Storm Lake. Little Storm Lake originally had the ability to remove much of the sediment and nutrients from incoming waters. However, due to degradation, proper wetland function has been compromised. Under normal hydrologic conditions Little Storm Lake has the potential to function as a sediment trap for Storm Lake, but tllis capacity is overwhelmed during high flows. Little Storm Lake is at or near its sediment trapping capacity, which results in higher sediment transport into Storm Lake. Resuspension of sediments due to wind and other in-lake dynamics, such as rough fish, further exacerbate the total turbidity from suspended sediment and results in movement of sediment from Little Storm Lake into Storm Lake. This project includes a fish barrier and water retention structure between Little Storm Lake and Storm Lake and the construction of a pumping station and associated equipment. The project involves periodic dewatering of Little Storm Lake during years of favorable climatological conditions to consolidate the sediments and revegetate the area. Construction of the fish banier would aid restoration efforts by preventing rough fish from destroying the vegetation and would decrease recruitment of rough fish by limiting their spawning area. In the future, if the diminished trapping capacity of Little Storm Lake still results in sediment moving into Storm Lake, a dredging project would be initiated to deepen Little Storm Lake.

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This project proposes a unique approach to addressing one of the more challenging issues facing efforts to protect water quality in Rathbun Lake; reducing sediment and phosphorus delivery from land on which best management practices (BMPs) will not be applied. This project will construct ten impoundments at key locations in the watershed to reduce the annual delivery of 2,970 tons of sediment and 12,100 pounds of phosphorus to Rathbun Lake. Features of this approach are: (a) impoundments will be constructed at sites below areas with high concentrations of priority land that has the greatest potential to deliver sediment and phosphorus to Rathbun Lake and on which landowners are unable or unwilling to apply BMPs and (b) strategically placed, large impoundments can be a cost effective means of reducing the sediment and phosphorus delivered to Rathbun Lake from priority land on which BMPs will not be applied. This project will significantly enhance the success of efforts underway in the Rathbun Lake Special Project as it addresses a critical water quality protection need that is not being met by current Special Project activities.

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Holiday Lake is included in the Walnut Creek watershed, which is listed on the 303(d) list of impaired water bodies. Research indicates that the causes of impairment are sedimentation and habitat alterations. To improve water quality, the goals of this project are to reduce the sediment delivery into Holiday Lake by 50% and assist in educating watershed residents about cost-effective ways to control sediment and nutrient contaminates. The best management practices will be installed to filter the water, reducing sediment and chemical loading into the lake. When all practices are installed, nearly 100% of the lake’s drainage area will be controlled.

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To understand dissolved organic carbon (DOC) seasonal dynamics in a coastal oligotrophic site in the north-western Mediterranean Sea, we monitored DOC concentrations monthly over 3 yr, together with the meteorological data and the food-web-related biological processes involved in DOC dynamics. Additional DOC samples were taken in several inshore−offshore transects along the Catalan coast. We found DOC concentrations of ~60 µmol C l−1 in winter, with increasing values through the summer and autumn and reaching 100 to 120 µmol C l−1 in November. There was high inter-annual variability in this summer DOC accumulation, with values of 36, 69 and 13 µmol C l−1 for 2006, 2007 and 2008, respectively. The analysis of the microbial food-web processes involved in the DOC balance did not reveal the causes of this accumulation, since the only occasion on which we observed net DOC production (0.3 ± 1 µmol C l−1 d−1 on average) was in 2007, and the negative DOC balance of 2006 and 2008 did not prevent DOC accumulating. The DOC accumulation episodes coincided with low rates of water renewal (average 0.037 ± 0.021 d−1 from May to October) compared with those of winter to early spring (average 0.11 ± 0.048 d−1 from November to April). Indeed, the amount of DOC accumulated each year was inversely correlated with the average summer rainfall. We hypothesize that decreased DOC turn-over due to photochemical or biological processes mostly active during the summer and low water renewal rate combine to determine seasonal DOC accumulation and influence its inter-annual variability.

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Using data from free listings and a survey in two villages of Tamil Nadu, India, we discuss local perceptions and uses of water tanks, a traditional irrigation infrastructure. We hypothesize that both farmers and nonfarmers perceive and use water tanks for purposes other than irrigation. We found that informants recognized the importance of water tanks for irrigation, but also acknowledged other socioeconomic uses and ecological functions. Marginal sectors (i.e., Scheduled Castes) use tank resources in more diverse ways than other sectors of the population. Findings are relevant for development. International organizations working on the revival of water tanks aim to transfer water management to farmers for the purpose of irrigation. By recognizing that tanks benefit people other than farmers and in ways other than providing irrigation water, organizations working on tank rejuvenation could achieve a more equitable management of tank resources.

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There is still limited understanding of the processes underlying benthic species dynamics in marine coastal habitats, which are of disproportionate importance in terms of productivity and biodiversity. The life-history traits of long-lived benthic species in these habitats are particularly poorly documented. In this study, we assessed decadal patterns of population dynamics for ten sponge and anthozoan species that play key structural roles in coralligenous outcrops (~25 m depth) in two areas of the NW Mediterranean Sea. This study was based on examination of a unique long-term photographic series, which allowed analysis of population dynamics over extensive spatial and time spans for the very first time. Specifically, 671 individuals were censused annually over periods of 25-, 15-, and 5-years. This long-term study quantitatively revealed a common life-history pattern among the ten studied species, despite the fact they present different growth forms. Low mortality rates (3.4% yr−1 for all species combined) and infrequent recruitment events (mean value of 3.1±0.5 SE recruits yr−1) provided only a very small fraction of the new colonies required to maintain population sizes. Overall, annual mortality and recruitment rates did not differ significantly among years; however, some species displayed important mortality events and recruitment pulses, indicating variability among species. Based on the growth rates of these 10 species, we projected their longevity and, obtained a mean estimated age of 25-200 years. Finally, the low to moderate turnover rates (mean value 0.80% yr−1) observed among the coralligenous species were in agreement with their low dynamics and persistence. These results offer solid baseline data and reveal that these habitats are among the most vulnerable to the current increases of anthropogenic disturbances.