Trophic state and water turn-over time in six choked coastal lagoons in Brazil

ABSTRACT High levels of eutrophication in coastal lagoons due to human activity have been documented worldwide. Among the main impacts observed are anoxia, hypoxia, toxic algal blooms, fish kills, loss of biodiversity and loss of bathing. This study aimed to evaluate the evolution of the trophic state of Lagoa da Conceição, a subtropical lagoon located in an urbanized watershed on the island of Santa Catarina - Brazil. Spatio temporal patterns of stratification and eutrophication were investigated to understand the main biochemical changes over time. The water quality data were obtained from field campaigns supplemented with literature of the last 15 years. The vertical structure of the water column and the trophic state were evaluated by the stratification index and the TRIX index, respectively. Analyses of variance were performed in order to identify possible temporal variations in vertical stratification and trophic level. Eutrophication effects on biogeochemical cycles were verified through a multi-dimensional cluster analysis (MDS) and correlations between variables related to physical, chemical and biological processes were verified by principal component analysis (PCA). The results showed that the water column is homogeneous in all regions except in the central region of the lagoon, and the highest ammonia concentrations and lowest dissolved oxygen concentrations with periods of anoxia are observed in bottom waters. The study looked at the high trophic level of the lagoon and its inability to process the biogeochemical changes imposed by urban development.

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Example application of a continuous lake trophic state index on lakes with limited data

10.7287/peerj.preprints.27913v1 ◽

2019 ◽

Cited By ~ 1

Author(s):

Farnaz Nojavan ◽

Betty J Kreakie ◽

Jeffrey W Hollister ◽

Song Qian

Keyword(s):

Multilevel Model ◽

Trophic State ◽

The United States ◽

Nutrient Concentrations ◽

Trophic State Index ◽

Gis Data ◽

Lake Trophic State ◽

State Index ◽

Multiple Metrics ◽

Over Time

Lake trophic state indices have long been used to provide a measure of the trophic state of lakes. Over time it has been determined that these indices perform better when they utilize multiple metrics and provide a continuous measurement of trophic state. We utilize such a method for trophic state that is based upon a Proportional Odds Logistic Regression (POLR) model and extend this model with a Bayesian multilevel model that predicts nutrient concentrations from universally available GIS data. This Bayesian multilevel model provides relatively accurate measures of trophic state and has an overall accuracy of 60%. The approach illustrates a method for estimating a continuous, mutli-metric trophic state index for any lake in the United States. Future improvements to the model will focus on improving overall accuracy and use variables that are more sensitive to change over time.

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The cycle of atmospheric nitrous oxide

Philosophical Transactions of the Royal Society of London. Series A, Mathematical and Physical Sciences ◽

10.1098/rsta.1979.0009 ◽

1979 ◽

Vol 290 (1376) ◽

pp. 495-504 ◽

Cited By ~ 9

Keyword(s):

Laboratory Experiments ◽

Nitrogen Fertilizers ◽

Time Range ◽

Microbial Activities ◽

Electrical Discharges ◽

Soil Systems ◽

To Come ◽

Turn Over ◽

Over Time ◽

Horizontal And Vertical Distribution

An attempt has been made to construct an N 2 O balance of the troposphere in order to demonstrate the state of knowledge of the cycle of atmospheric N 2 O. This balance has been constructed considering the parameters relevant for atmospheric N 2 O as far as known such as the horizontal and vertical distribution in the atmosphere and in the oceans, the variation of the atmospheric mixing ratio with time, the fluxes in the air-sea and in the air-soil systems, and man-made fluxes. The total atmospheric burden of N 2 O appears to be in the range 1600-2100 Mt, the tropospheric turn-over time between 4 and 12 years. Most of the atmospheric N 2 O seems to originate from microbial activities at the Earth’s surface with the oceans apparently being the major source with about 35 % of the total source as obtained from the tropospheric N 2 O mass and turn-over time (range of uncertainty 5-100 %) followed by soil and fresh water with about 25 % of the total source (range of uncertainty 4-100 %) including the contribution of industrial nitrogen fertilizers with about 10 % of the total source (range of uncertainty 2-24 %). Direct man-made N 2 O sources seem to be relatively small with about 2 % of the total source (range of uncertainty 0.5-5 %), but may grow considerably in the future. The N 2 O production by chemical reactions in the troposphere itself (e.g. electrical discharges) is not known; a figure of between 3 and 70 % of the total source has been inferred from laboratory experiments. The sinks of atmospheric N 2 O are poorly known. The only known major N 2 O destruction appears to occur in the stratosphere. The rate of transport into the stratosphere, however, limits this sink to about 10 % of the total amount of N 2 O to be destroyed under steady state conditions (range of uncertainty 3-22 %). The major problem of the cycle of atmospheric N 2 O is the unknown main sink. Since the stratosphere does not seem to come into question, the missing sink should be found somewhere in the troposphere, pedosphere, and/or hydrosphere.

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Ramp disturbance - ramp response: a simple model for wetland disturbance ecology

Marine and Freshwater Research ◽

10.1071/mf03026 ◽

2004 ◽

Vol 55 (1) ◽

pp. 33 ◽

Cited By ~ 6

Author(s):

David G. Angeler ◽

Maria A. Rodrigo

Keyword(s):

Trophic State ◽

Gradual Increase ◽

Disturbance Ecology ◽

Water Levels ◽

Model Organisms ◽

Drought Event ◽

Floodplain Wetland ◽

Synechococcus Sp ◽

Over Time ◽

Ramp Response

In the present study, we report on the responses of the picoplanktonic cyanoprokaryote Synechococcus sp. to a summer drawdown in a Mediterranean floodplain wetland, using water level decrease as a measure of the gradual increase of disturbance over time, defined as a ramp disturbance. Simulating the gradual confinement of fish biomass during the drought event in an enclosure study, we found that the density of Synechococcus did not change significantly in response to fish-mediated changes in trophic state and food web compared with a fishless control. Instead, we observed a positive correlation of water levels and Synechococcus abundance in all enclosures, indicative of a ramp response to the ramp disturbance. Planktonic organisms, although largely neglected by wetland scientists, seem to be very useful model organisms for identifying cause–effect mechanisms in wetland disturbance ecology.

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Visualizing differential principal turnover

Journal of Educational Administration ◽

10.1108/jea-03-2020-0054 ◽

2020 ◽

Vol ahead-of-print (ahead-of-print) ◽

Author(s):

Bradley Davis ◽

Erin Anderson

Keyword(s):

Data Visualization ◽

Educational Administration ◽

School Principals ◽

School Level ◽

Complex Data ◽

Content Type ◽

Principal Turnover ◽

Turn Over ◽

First Time ◽

Over Time

PurposeThe authors demonstrate the usage of data visualization for conveying educational administration research, with a specific focus on differential principal turnover. They model when and how principals move, over time, between six categories of turnover.Design/methodology/approachThe authors construct several easy-to-interpret alluvial diagrams that reveal the patterns of differential turnover among 1,113 first-time Texas principals. Furthermore, the authors investigate how these patterns differ across educator characteristics (i.e. race and sex) and school contexts (i.e. school level and campus urbanicity).FindingsHalf of all first-time principals turn over within two years. Most principals who stay in leadership roles leave the district where they were first entered the principalship. Men are promoted more and women turn over less. In a connected finding, the authors conclude that elementary principals turn over less, and middle and high school principals are promoted more often. Principals of color are demoted more often than White principals. Urban school principals exit the system at a greater rate than rural principals.Originality/valueThe significance of this study lies in its direct response to two problems facing the administrator turnover knowledge base – a lack of methodological accessibility and the underutilization of data visualization. The authors’ is the first study to contain visualization of differential turnover outcomes over time. Second, the authors’ study provides a blueprint for data visualization that not only creates new knowledge but also speaks to a wider variety of education stakeholders by presenting complex data in a visual format.

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Color changes in beef meat during pan cooking: kinetics, modeling and application to predict turn over time

European Food Research and Technology ◽

10.1007/s00217-021-03821-y ◽

2021 ◽

Author(s):

Jara Moya ◽

Silvia Lorente-Bailo ◽

Ana Ferrer-Mairal ◽

Miguel A. Martínez ◽

Begoña Calvo ◽

...

Keyword(s):

Color Space ◽

Response Surfaces ◽

Color Changes ◽

Beef Meat ◽

Color Profile ◽

Turn Over ◽

Cooked Meat ◽

Kinetics Of ◽

Evolution With Time ◽

Over Time

AbstractThe kinetics of heat-induced color changes in beef meat was determined and implemented in a numerical model for double-sided pan cooking of steak. The CIELab color space was used to obtain the lightness (coordinate $$L^*$$ L ∗ ) and the reddish tone (coordinate $$a^*$$ a ∗ ) of the cooked meat. $$L^*$$ L ∗ was the CIELab coordinate that contributed the most to the change in the absolute color. Two response surfaces were found to describe the evolution with time and temperature of both color coordinates, $$L^*$$ L ∗ and $$a^*$$ a ∗ . The model results were successfully verified with experimental data of the two coordinates along the thickness of the meat for three degrees of cooking. The Root-Mean-Squared Errors (RMSE) for coordinate $$L^*$$ L ∗ were 5.17 (very rare), 2.02 (medium rare) and 3.83 (done), and for coordinate $$a^*$$ a ∗ 1.44 (very rare), 1.26 (medium rare) and 0.89 (done). The applicability of the model for practical cooking purposes was illustrated by determining the optimum turn over time to achieve a similar color profile on both sides of the meat. The turn over time depended on the desired degrees of cooking, and were comprised between one-half and two-thirds of the final cooking time, increasing from very rare cooking degree to done cooking degree.

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Overview on Miss Management in Turn over Time in Orthopaedic Operative Room

Health Care Current Reviews ◽

10.4172/2375-4273.1000224 ◽

2018 ◽

Vol 06 (02) ◽

Author(s):

Zandi R ◽

Ebrahimpour A ◽

Sajadi MM ◽

Sedighi M ◽

Okhovatpour MA ◽

...

Keyword(s):

Turn Over ◽

Over Time

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Thomas Twyne's Appropriation of Thomas Phaer's Æneidos: ‘Worke unperfyt’ Perfected?

Translation and Literature ◽

10.3366/tal.2018.0352 ◽

2018 ◽

Vol 27 (3) ◽

pp. 287-305

Author(s):

Susanna Braund

Keyword(s):

English Translation ◽

Limited Evidence ◽

Turn Over ◽

Similar Kind ◽

Over Time

Abstract: This paper attempts to reconstruct from the limited evidence available the rationale and development of Thomas Twyne's completion (1573–84) of Thomas Phaer's unfinished English translation of the Aeneid (1555–60). In Phaer's hands, it is suggested, ‘continuation’ and ‘completion’ gradually turn over time into ‘competition’, ‘absorption’, and even ‘appropriation’. A key element in this process is Phaer's decision to add to the twelve books of Virgil's epic his translation of Maffeo Vegio's Latin Supplementum (1428): Twyne brings a similar kind of closure to Phaer's project to that involved in Vegio's Aeneid Book 13.

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Assembly and turnover of detyrosinated tubulin in vivo.

The Journal of Cell Biology ◽

10.1083/jcb.105.1.265 ◽

1987 ◽

Vol 105 (1) ◽

pp. 265-276 ◽

Cited By ~ 65

Author(s):

D R Webster ◽

G G Gundersen ◽

J C Bulinski ◽

G G Borisy

Keyword(s):

Dynamic Instability ◽

Human Fibroblasts ◽

Chinese Hamster ◽

Living Cells ◽

Complete Loss ◽

Almost All ◽

Turn Over ◽

Fixed Times ◽

Over Time

Detyrosinated (Glu) tubulin was prepared from porcine brain and microinjected into human fibroblasts and Chinese hamster ovary (CHO) cells. Glu tubulin assembled onto the ends of preexisting microtubules and directly from the centrosome within minutes of its microinjection. Incorporation into the cytoskeleton continued until almost all of the microtubules were copolymers of Glu and tyrosinated (Tyr) tubulin. However, further incubation resulted in the progressive and ultimately complete loss of Glu-staining microtubules. Glu tubulin injected into nocodazole-treated cells was converted to Tyr tubulin by a putative tubulin/tyrosine ligase activity. The observed decrease in staining with the Glu antibody over time was used to analyze microtubule turnover in microinjected cells. The mode of Glu disappearance was analyzed quantitatively by tabulating the number of Glu-Tyr copolymers and Tyr-only microtubules at fixed times after injection. The proportion of Glu-Tyr copolymers decreased progressively over time and no segmentally labeled microtubules were observed, indicating that microtubules turn over rapidly and individually. Our results are consistent with a closely regulated tyrosination-detyrosination cycle in living cells and suggest that microtubule turnover is mediated by dynamic instability.

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