Ice breakup: a neglected factor in river ecology

2003 ◽  
Vol 30 (1) ◽  
pp. 128-144 ◽  
Author(s):  
Terry D Prowse ◽  
Joseph M Culp
Keyword(s):  
Time Frame ◽  
River Ice ◽  
Reference Source ◽  
River Ecology ◽  
Cold Regions ◽  
Streams And Rivers ◽  
Ice Breakup ◽  
Ecological Aspects ◽  
Biotic Effects

To minimize environmental impacts that may result from any engineered modifications of stream or river systems, a basic understanding of river ecology is required. Most fundamental theories of river ecology have developed largely from studies of warm-temperate and tropical streams and rivers. As these theories evolved over the last few decades, floods were recognized increasingly as dominant hydrologic events that control numerous abiotic and biotic forms and processes, both within the channel and on the adjacent riparian floodplains. Over approximately the same time frame, river-ice breakup was shown to be a major, if not predominant, source of floods on cold-regions rivers. Despite this, rarely has the role of ice-induced flooding been considered by subsequent modifications to the original theories or in the extensive studies and literature that they spawned. This manuscript reviews the broad, although frequently anecdotal, information about the abiotic and biotic effects of breakup processes and flooding. Based on this, it argues for breakup to be incorporated in future advancements of river ecological theory. The extensive list of cited studies provides a valuable reference source for scientists and engineers assessing development-related impacts on cold-regions streams and rivers, or further researching ecological aspects of river-ice breakup.Key words: river ice, river ecology, freshwater ecology, flooding, breakup, ice jam.

scholarly journals Impact of Climate Change on the Frequency of Dynamic Breakup Events and on the Risk of Ice-Jam Floods in Quebec, Canada

Water ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2891 ◽  
Author(s):  
Benoit Turcotte ◽  
Brian Morse ◽  
Gabriel Pelchat
Keyword(s):  
Climate Change ◽  
Financial Risk ◽  
Climate Change Impacts ◽  
Flood Damage ◽  
River Ice ◽  
Climate Projections ◽  
Cold Regions ◽  
Ice Jams ◽  
Ice Jam ◽  
Ice Breakup

In cold regions, every year, river-ice jams generate sudden, surprising, intense flooding that challenges the capacity of public security services. This type of flood is commonly unpredictable and often appears chaotic because its occurrence depends on multiple, interacting weather, hydrological, ice and morphological parameters. This paper presents the findings of a research project assessing how climate change impacts dynamic river-ice breakup and associated floods along seven rivers of the province of Quebec, Canada. A combination of empirical river-ice breakup models, state-of-the-art hydrological simulations and standardized climate projections was used to estimate the historical (1972–2000) and future (2042–2070) frequencies of dynamic breakup events. Ice jam flood damage reimbursement data were used to predict changes to financial risk associated with dynamic breakup events. Results show that, overall, ice-jam floods will generate more damage in the future, which justifies watershed-based flood adaptation plans that take into account cold regions hydrological processes. The success of the methodology also sets the table for a comparable project that would include more rivers from different regions of Northeastern America.

scholarly journals Testing the spatial and temporal framework of speciation in an ancient lake species flock: the leech genus <i>Dina</i> (Hirudinea: Erpobdellidae) in Lake Ohrid

2010 ◽  
Vol 7 (11) ◽  
pp. 3387-3402 ◽  
Author(s):  
S. Trajanovski ◽  
C. Albrecht ◽  
K. Schreiber ◽  
R. Schultheiß ◽  
T. Stadler ◽  
...  
Keyword(s):  
Molecular Clock ◽  
Abiotic Factors ◽  
Time Frame ◽  
Recent Common Ancestor ◽  
Species Flock ◽  
Ancient Lake ◽  
Lake Ohrid ◽  
Most Recent Common Ancestor ◽  
Extant Species

Abstract. Ancient Lake Ohrid on the Balkan Peninsula is considered to be the oldest ancient lake in Europe with a suggested Plio-/Pleistocene age. Its exact geological age, however, remains unknown. Therefore, molecular clock data of Lake Ohrid biota may serve as an independent constraint of available geological data, and may thus help to refine age estimates. Such evolutionary data may also help unravel potential biotic and abiotic factors that promote speciation events. Here, mitochondrial sequencing data of one of the largest groups of endemic taxa in the Ohrid watershed, the leech genus Dina, is used to test whether it represents an ancient lake species flock, to study the role of potential horizontal and vertical barriers in the watershed for evolutionary events, to estimate the onset of diversification in this group based on molecular clock analyses, and to compare this data with data from other endemic species for providing an approximate time frame for the origin of Lake Ohrid. Based on the criteria speciosity, monophyly and endemicity, it can be concluded that Dina spp. from the Ohrid watershed, indeed, represents an ancient lake species flock. Lineage sorting of its species, however, does not seem to be complete and/or hybridization may occur. Analyses of population structures of Dina spp. in the Ohrid watershed indicate a horizontal zonation of haplotypes from spring and lake populations, corroborating the role of lake-side springs, particularly the southern feeder springs, for evolutionary processes in endemic Ohrid taxa. Vertical differentiation of lake taxa, however, appears to be limited, though differences between populations from the littoral and the profundal are apparent. Molecular clock analyses indicate that the most recent common ancestor of extant species of this flock is approximately 1.99 ± 0.83 million years (Ma) old, whereas the split of the Ohrid Dina flock from a potential sister taxon outside the lake is estimated at 8.30 ± 3.60 Ma. Comparisons with other groups of endemic Ohrid species indicated that in all cases, diversification within the watershed started ≤2 Ma ago. Thus, this estimate may provide information on a minimum age for the origin of Lake Ohrid. Maximum ages are less consistent and generally less reliable. But cautiously, a maximum age of 3 Ma is suggested. Interestingly, this time frame of approximately 2–3 Ma ago for the origin of Lake Ohrid, generated based on genetic data, well fits the time frame most often used in the literature by geologists.

Ice jam mitigation

1990 ◽  
Vol 17 (5) ◽  
pp. 675-685 ◽  
Author(s):  
Harold S. Belore ◽  
Brian C. Burrell ◽  
Spyros Beltaos
Keyword(s):  
Key Words ◽  
Carrying Capacity ◽  
Flood Control ◽  
Human Life ◽  
Water Levels ◽  
Economic Losses ◽  
River Ice ◽  
Ice Jams ◽  
Ice Jam ◽  
Ice Breakup

In Canada, flooding due to the rise in water levels upstream of an ice jam, or the temporary exceedance of the flow and ice-carrying capacity of a channel upon release of an ice jam, has resulted in the loss of human life and extensive economic losses. Ice jam mitigation is a component of river ice management which includes all activities carried out to prevent or remove ice jams, or to reduce the damages that may result from an ice jam event. This paper presents a brief overview of measures to mitigate the damaging effects of ice jams and contains a discussion on their application to Canadian rivers. Key words: controlled ice breakup, flood control, ice jams, ice management, river ice.

scholarly journals Analytical and diagnostic performances of a high-throughput immunoassay for SARS-CoV-2 IgM and IgG

2020 ◽  
Author(s):  
Andrea Padoan ◽  
Chiara Cosma ◽  
Paolo Zaupa ◽  
Mario Plebani
Keyword(s):  
Sensitivity And Specificity ◽  
Symptom Onset ◽  
Severe Disease ◽  
Onset Time ◽  
Time Frame ◽  
Serum Samples ◽  
Time Period ◽  
Analytical Imprecision ◽  
Range Of Values

BackgroundAbstractReliable SARS-CoV-2 serological assays are required for diagnosing infections, for the serosurveillance of past exposures and for assessing the response to future vaccines. In this study, the analytical and clinical performances of a chemiluminescent immunoassays for SARS-CoV-2 IgM and IgG detection (Mindray CL-1200i), targeting Nucleocapsid (N) and receptor binding domain (RBD) portion of the Spike protein, were evaluated.MethodsPrecision and linearity were evaluated using standardized procedures. A total of 157 leftover serum samples from 81 hospitalized confirmed COVID-19 patients (38 with moderate and 43 with severe disease) and 76 SARS-CoV-2 negative subjects (44 healthcare workers, 20 individuals with rheumatic disorders, 12 pregnant women) were included in the study. In an additional series of 44 SARS-CoV-2 positive, IgM and IgG time kinetics were also evaluated in a time-period of 38 days.ResultsPrecision was below or equal to 4% for both IgM and IgG, in all the studied levels, whilst a slightly significant deviation from linearity was observed for both assays in the range of values covering the manufacturer’s cut-off. Considering a time frame ≥ 12 days post symptom onset, sensitivity and specificity for IgM were 92.3% (95%CI:79.1%-98.4%) and 92.1% (95%CI:83.6%-97.0%). In the same time frame, sensitivity and specificity for IgG were 100% (95%CI:91.0%-100%) and 93.4% (95%CI:85.3%-97.8%). The assays agreement was 73.9% (Cohen’s kappa of 0.373). Time kinetics showed a substantial overlapping of IgM and IgG response, the latter values being elevated up to 38 days from symptoms onset.ConclusionsAnalytical imprecision is satisfactory as well as the linearity, particularly when taking into account the fact that both assays are claimed to be qualitative. Diagnostic sensitivity of IgG was excellent, especially considering specimens collected ≥12 days post symptom onset. Time kinetics suggest that IgM and IgG are detectable early in the course of infection, but the role of SARS-CoV-2 antibodies in clinical practice still requires further evaluations.

scholarly journals MODEL EKONOMI-EKOLOGI BERDASARKAN WTP PENGUNJUNG-WTA MASYARAKAT LOCAL DALAM PENGELOLAAN DESTINASI WISATA GUNUNG API BAWAH LAUT MAHENGETANG, KABUPATEN SANGIHE

2017 ◽  
Vol 13 (3) ◽  
pp. 7
Author(s):  
Paulus Adrian Pangemanan ◽  
Gene H. M. Kapantouw
Keyword(s):  
Local Community ◽  
Local Communities ◽  
Management Model ◽  
Tourist Destinations ◽  
Resource Sustainability ◽  
Ecological Aspects ◽  
Ecological Improvement ◽  
Alternative Activities ◽  
Economic Improvement

Continuing management of tourist destinations, integrating economic and ecological aspects, and involving quadrohelical roles: local communities, tourism businesses, government and universities. This research develops a tourism destination management model that integrates economic and ecological development based on visitor willingness to pay (WTP) attachment with willingness to accept (WTA) of local community, supported by business actor role and government. Colleges play a role in identifying ecological and economic elements, analyzing and formulating alternative development activities that ensure economic improvement for local communities and resource sustainability (natural, socio-cultural) to improve the destination's life cycle. The purpose of this research is to manage the role of quadrohelical tourism in evaluating, developing economic programs / activities for the surrounding community, by prioritizing the sustainability of resource ecosystem. This research was conducted for 10 months in the area of Mahengetang submarine volcano in Sangihe District. This study focuses on identifying existing conditions of economic and ecological elements, analysis and formulation of alternative activities for economic and ecological improvement based on indicators (WTP-WTA). Destination management model based on WTP-WTA with integrated role of quadrohelical system can be adapted and developed in other destination, or in other resource utilization.

scholarly journals Cell surface oligosaccharides on Dictyostelium during development

1991 ◽  
Vol 99 (3) ◽  
pp. 485-495
Author(s):  
SUPAVADEE AMATAYAKUL-CHANTLER ◽  
MICHAEL A. J. FERGUSON ◽  
RAYMOND A. DWEK ◽  
THOMAS W. RADEMACHER ◽  
RAJ B. PAREKH ◽  
...  
Keyword(s):  
Cell Surface ◽  
Time Frame ◽  
Protein Glycosylation ◽  
Developmental Studies ◽  
Plant Glycoproteins ◽  
Chemical Technique ◽  
Cell Surface Glycoproteins ◽  
Oligosaccharide Structures ◽  
Surface Glycoproteins

Developmental studies of the changes in protein glycosylation are useful in elucidating the role of oligosaccharides in biological events. We have used the chemical technique, hydrazinolysis, to release oligosaccharides from cell surface glycoproteins of Dictyostelium discoideum. Oligomannose type, xylose- and fucose-containing oligosaccharides were found to be present. The charged oligosaccharides contained sulphate and mannose 6-phosphate residues; no sialic acid was detected. The charged oligosaccharides also contained significant amounts of xylose, arabinose, fucose and galactose, as well as mannose and N-acetylglucosamine, which were the main constituents of the neutral glycans. By monitoring the chemical characteristics of the liberated oligosaccharides, dramatic changes in both the charge and size distribution of cell surface oligosaccharides were observed throughout the 24 h period of cell development. A comparison, however, between the neutral glycan structures of prestalk and prespore cells, over the same time frame showed no dramatic differences Discoidin, a lectin present on the cell surface of 8 h cells, was found not to be glycosylated. Affinity chromatography using immobilised discoidin was used to probe a sugar library made from the cell surface glycoproteins of 8h cells. Discoidin was found to bind selectively an oligosaccharide with the structure Manα3(Manα6)(Xylβ2)Manβ4GlcNAc. This oligosaccharide lacks a conventional N,N'-diacetylchitobiose core and has only been previously observed in plant glycoproteins. Peptide-N-glycosidase F treatment of horseradish peroxidase released an identical structure, confirming that the oligosaccharide was not a degradation fragment of the hydrazine. The oligosaccharide was found to inhibit discoidinmediated haemagglutination with a Kt of 0.75 mM, a concentration approximately 100 times lower than that for galactose The correlation between changes in the amoebal plasma membrane oligosaccharide structures and the biological events occurring at different stages of development such as cell-cell adhesion and cellsubstratum attachment suggest an important role for sugars in these processes

scholarly journals Testing the spatial and temporal framework of speciation in an ancient lake species flock: the leech genus <i>Dina</i> (Hirudinea: Erpobdellidae) in Lake Ohrid

2010 ◽  
Vol 7 (4) ◽  
pp. 5011-5045 ◽  
Author(s):  
S. Trajanovski ◽  
C. Albrecht ◽  
K. Schreiber ◽  
R. Schultheiß ◽  
T. Stadler ◽  
...  
Keyword(s):  
Molecular Clock ◽  
Abiotic Factors ◽  
Time Frame ◽  
Recent Common Ancestor ◽  
Species Flock ◽  
Ancient Lake ◽  
Lake Ohrid ◽  
Most Recent Common Ancestor ◽  
Extant Species

Abstract. Ancient Lake Ohrid on the Balkan Peninsula is considered to be the oldest ancient lake in Europe with a suggested Plio-Pleistocene age. Its exact geological age, however, remains unknown. Therefore, molecular clock data of Lake Ohrid biota may serve as an independent constraint of available geological data, and may thus also help to refine age estimates. Such evolutionary data may also help unravel potential biotic and abiotic factors that promote speciation events. Here, mitochondrial sequencing data of one of the largest groups of endemic taxa in Lake Ohrid, the leech genus Dina, is used to test whether it represents an ancient lake species flock, to study the role of horizontal and vertical barriers in Lake Ohrid for evolutionary events, to estimate the onset of intralacustrine diversification in this group based on molecular clock analyses, and to compare this data with data from other endemic species for providing an approximate time frame for the origin of Lake Ohrid. Based on the criteria speciosity, monophyly and endemicity, it can be concluded that Lake Ohrid Dina, indeed, represents an ancient lake species flock. Lineage sorting of its species, however, does not seem to be complete. Analyses of population structures of Dina spp. in the Ohrid watershed indicate a horizontal zonation of haplotypes from spring and lake populations, corroborating the role of lake-side springs, particularly the southern feeder springs, for evolutionary processes in endemic Ohrid taxa. Vertical differentiation of lake taxa, however, appears to be limited, though differences between populations from the littoral and the profundal are apparent. Molecular clock analyses indicate that the most recent common ancestor of extant species of this flock is approximately 1.99±0.83 Ma old, whereas the split of the Lake Ohrid Dina flock from a potential sister taxon outside the lake is estimated at 8.30±3.60 Ma. Comparisons with other groups of endemic Ohrid species indicated that in all cases, intralacustrine diversification started ≤2 Ma ago. Thus, this estimate may provide information on a minimum age for the origin of Lake Ohrid. Maximum ages are less consistent and generally less reliable. But cautiously, a maximum age of 3 Ma is suggested. Interestingly, this time frame of approximately 2–3 Ma for the origin of Lake Ohrid, generated based solely on evolutionary data, well fits the time frame most often used in the literature by geologists. Future studies must show whether this concurrence holds true.

Experience in developing a method for long-term forecasting of the ice breakup time for the Vyatka River basin

2021 ◽  
Vol 4 ◽  
pp. 99-111
Author(s):  
Y.A Pavroz . ◽  
Keyword(s):  
Surface Temperature ◽  
Sea Surface Temperature ◽  
River Basin ◽  
Geopotential Height ◽  
Sea Surface ◽  
River Ice ◽  
Northwest Pacific ◽  
Ice Breakup ◽  
The Impact ◽  
Breakup Time

An attempt is made to develop a method for long-term forecasting of the ice breakup time for the Vyatka River basin, to identify the impact of the distribution of sea surface temperature and geopotential height in the informative regions at the levels H100 and H500 over the Northern Hemisphere on the river ice breakup. The location and boundaries of the informative regions in the fields of H100 and H500 were revealed by the discriminant analysis, the EOF expansion coefficients of the fields of anomalies of monthly mean values of H100 and H500 for January and February and the anomalies of monthly mean sea surface temperature in the North Atlantic and Northwest Pacific were used as potential predictors. The stepwise regression analysis allowed deriving good and satisfactory (S/σ = 0.45–0.73) complex prognostic equations for forecasting the ice breakup time for the Vyatka River basin. The essential influence of H100 and H500 geopotential height fields and the spatial distribution of sea surface temperature anomalies in the North Atlantic and Northwest Pacific in January and February on the river ice breakup time is revealed. It is proposed to improve the method by considering the impact of air temperature, maximum ice thickness per winter, and other indirect characteristics on the processes of river ice breakup in the Vyatka River basin. Keywords: ice regime, long-range forecast, river ice breakup, expansion coefficients, geopotential height fields, spring ice phenomena, energy-active zones of the oceans, complex prognostic equation

A Descriptive Study of Chaplains’ Code Blue Responses

2021 ◽  
Vol 30 (6) ◽  
pp. 419-425
Author(s):  
Carolina D. Tennyson ◽  
John P. Oliver ◽  
Karen R. Jooste
Keyword(s):  
Spiritual Care ◽  
Family Members ◽  
Time Frame ◽  
Respiratory Arrest ◽  
Health Care Team ◽  
Patient Death ◽  
Bereavement Support ◽  
Family Presence ◽  
Code Blue

Background Family presence during resuscitation is the compassionate practice of allowing a patient’s family to witness treatment for cardiac or respiratory arrest (code blue event) when appropriate. Offering family presence during resuscitation as an interprofessional practice is consistent with patient- and family-centered care. In many institutions, the role of family facilitator is not formalized and may be performed by various staff members. At the large academic institution of this study, the family facilitator is a member of the chaplain staff. Objectives To examine the frequency of family presence during code blue events and describe the role of chaplains as family facilitators. Methods Chaplain staff documented information about their code responses daily from January 2012 through April 2020. They documented their response time, occurrence of patient death, presence of family at the event, and services they provided. A retrospective data review was performed. Results Chaplains responded to 1971 code blue pages during this time frame. Family members were present at 53% of code blue events. Chaplains provided multiple services, including crisis support, compassionate presence, spiritual care, bereavement support, staff debriefing, and prayer with and for patients, families, and staff. Conclusions Family members are frequently present during code blue events. Chaplains are available to respond to all such events and provide a variety of immediate and longitudinal services to patients, families, and members of the health care team. Their experience in crisis management, spiritual care, and bereavement support makes them ideally suited to serve as family facilitators during resuscitation events.

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