scholarly journals Does habitat restoration disturb? A case study of a shallow urban water reservoir in western India using cladoceran zooplankton.

2021 ◽  
Author(s):  
Mihir R. Kulkarni ◽  
Sameer M Padhye
Keyword(s):  
Habitat Restoration ◽  
Habitat Degradation ◽  
Late Phase ◽  
Water Reservoir ◽  
Western India ◽  
Urban Water ◽  
Cladoceran Species ◽  
Functional Richness ◽  
Two Phases ◽  
Cladoceran Zooplankton

Anthropogenic stressors, including restoration activities, can have ecosystem wide impacts, reflecting in various biotic components, particularly the basal levels in the trophic webs. Functional traits link taxonomic diversity to ecosystem function, thereby enabling a better ecological assessment of ecosystem health. We studied the effects of restoration activities on the community structure and functional diversity of freshwater cladoceran zooplankton in an urban water reservoir. Samples were taken in the early and late phases of the restoration work. Cladoceran species community and functional composition was significantly different between the two phases. There was a considerable reduction in taxonomic richness, functional richness and redundancy in the late phase. Taxonomic beta diversity between the two phases was explained more by nestedness. Habitat degradation due to haphazard restoration measures such as destruction of littoral zone and arbitrary desilting in addition to the dumping of untreated sewage could have contributed to the decrease in species and functional richness within the reservoir.

scholarly journals Innovative approach for achieving of sustainable urban water supply system by using of solar photovoltaic energy

2017 ◽  
Vol 37 (1) ◽  
pp. 58 ◽  
Author(s):  
Jure Margeta ◽  
Bojan Đurin
Keyword(s):  
Water Supply ◽  
Urban Areas ◽  
Renewable Energy Sources ◽  
Water Reservoir ◽  
Supply System ◽  
Water Supply System ◽  
Urban Water ◽  
Solar Photovoltaic ◽  
Urban Water Supply ◽  
Pump Station

Paper describes and analyses new and innovative concept for possible integration of solar photovoltaic (PV) energy in urban water supply system (UWSS). Proposed system consists of PV generator and invertor, pump station and water reservoir. System is sized in such a manner that every his part is sized separately and after this integrated into a whole. This integration is desirable for several reasons, where the most important is the achievement of the objectives of sustainable living in urban areas i.e. achieving of sustainable urban water supply system. The biggest technological challenge associated with the use of solar, wind and other intermittent renewable energy sources RES is the realization of economically and environmentally friendly electric energy storage (EES). The paper elaborates the use of water reservoires in UWSS as EES. The proposed solution is still more expensive than the traditional and is economically acceptable today in the cases of isolated urban water system and special situations. Wider application will depend on the future trends of energy prices, construction costs of PV generators and needs for CO2 reduction by urban water infrastructure.

Pacific Salmon Environmental and Life History Models: Advancing Science for Sustainable Salmon in the Future

2009 ◽  
Keyword(s):  
Life History ◽  
Iterative Process ◽  
Human Population ◽  
Habitat Restoration ◽  
Oncorhynchus Tshawytscha ◽  
Habitat Degradation ◽  
Pacific Salmon ◽  
Puget Sound ◽  
Habitat Conditions ◽  
Restoration And Protection

<em>Abstract.</em>—The Washington Department of Fish and Wildlife and Tribal co-managers are using the Ecosystem Diagnosis and Treatment (EDT) model to identify the spatial and temporal habitat limits of salmon populations and predict the effects of proposed habitat restoration projects for ESA-listed Chinook salmon <em>Oncorhynchus tshawytscha </em>in two Puget Sound watersheds. The collaborative, iterative process focused on habitat-based population models for the Dungeness and Dosewallips watersheds. Workshops were held to develop quantitative characteristics of current, historic, hypothetical properly functioning, and future habitat conditions. The model predicted salmon populations in the watersheds for each set of habitat conditions. Recovery targets were based on the predicted populations for historic and hypothetical properly functioning conditions. Future populations were modeled using projected habitat conditions with individual habitat restoration and protection actions already proposed and combinations of these actions. Populations resulting from further habitat degradation were estimated using the effects of projected human population growth on habitat.

Simulation of the TMI-2 Accident With ATHLET-CD and Analysis of the Late-Phase Modeling

2012 ◽  
Author(s):  
Mathias Hoffmann ◽  
Marco K. Koch
Keyword(s):  
Hydrogen Generation ◽  
Late Phase ◽  
Current Version ◽  
Molten Material ◽  
Plant Behavior ◽  
Accident Data ◽  
Core Components ◽  
Molten Materials ◽  
Two Phases ◽  
Reactor Pressure

This paper provides the results of a simulation of the TMI-2 accident with the current version of ATHLET-CD Mod. 2.2A as part of code validation activities at Ruhr-Universität Bochum (RUB). The calculated plant behavior during the first four phases of the accident is discussed and analyzed in comparison to available post-accident data and measurements. The calculation captures the plant response in terms of the thermal-hydraulics very well during the first two phases. However, during the reflooding of the degraded core some discrepancies between the calculation and TMI-2 data are identified. The code basically underestimates the hydrogen generation in this phase. Moreover, the debris bed and molten pool behavior during this phase cannot be simulated yet. An essential limitation of the current capabilities of the code in terms of the late-phase is the lack of models addressing the relocation of molten materials to the lower plenum of the reactor pressure vessel. Based on this analysis, the next steps needed to model the relocation of molten core components to the lower plenum are identified. These are the lateral leveling of accumulated molten material inside molten pools as well as the slumping to the lower plenum via different paths.

Evidence for the involvement of the optic nerve as a migration route for larvae in ocular toxocariasis of Mongolian gerbils

2003 ◽  
Vol 77 (4) ◽  
pp. 311-315 ◽  
Author(s):  
E. Hayashi ◽  
N. Akao ◽  
K. Fujita
Keyword(s):  
Optic Nerve ◽  
Late Phase ◽  
Toxocara Canis ◽  
Meriones Unguiculatus ◽  
Migration Route ◽  
Mongolian Gerbils ◽  
Ocular Toxocariasis ◽  
Optic Chiasma ◽  
Two Phases ◽  
The Brain

AbstractAlthough Toxocara canis, an important pathogen of ocular disease, tends to migrate to the eye, the precise migratory route has yet to be determined experimentally. Mongolian gerbils, Meriones unguiculatus, known as a useful animal model for human toxocariasis, were used to investigate the migration route toward the eyes. Infective larvae of T. canis were directly inoculated into the intracranial region. Haemorrhagic lesions or larvae were observed in 56.3% of cases. Histopathologically, a larva was observed in the optic nerve of gerbils 6 days after inoculation, and two larvae were found in the optic chiasma in the gerbils having a haemorrhage in the retina 9 days after inoculation. These results indicate that T. canis migrates from the brain to the eye through the optic nerve. Considering these data and previous studies showing that the ocular changes appear as early as 3 days of infection in the oral-administrated gerbils, there are two phases in the migration to the retina: a haematogenous early phase and an optic nerve route late phase.

scholarly journals Optimization of water reservoir volume in an urban water supply system

2021 ◽  
Author(s):  
Lucija Plantak ◽  
Bojan Đurin ◽  
Tatjana Džeba ◽  
Sara Dadar
Keyword(s):  
Water Supply ◽  
Water Consumption ◽  
Water Reservoir ◽  
Supply System ◽  
Water Supply System ◽  
Urban Water ◽  
Urban Water Supply ◽  
Functional Relationships ◽  
Reservoir Volume ◽  
Water Pumping

In this paper, the water pumping regime, as well as the water consumption regime with regard to the required quantities and the example of water consumption, with an emphasis on changes in water volume, are examined. This aims to show the functioning of the regime of water consumption, water pumping, as well as finding functional relationships between the mentioned sizes and the volume of the water reservoir. The analysis focuses on questions such as how and in what way, changes in the onset and duration of pumping, as well as different water consumption regimes affect the size of the reservoir volume. The entire analysis in this paper was done to develop a scientifically innovative, but also applicable mathematical model, which is a contribution to the profession and a good basis for further scientific research to improve the operation of the urban water supply system.

Status, Distribution, and Conservation of Native Freshwater Fishes of Western North America

2007 ◽  
Keyword(s):  
North America ◽  
Native Species ◽  
Salmo Trutta ◽  
Habitat Restoration ◽  
Habitat Degradation ◽  
Freshwater Fishes ◽  
Western North America ◽  
The Status ◽  
Bonneville Basin ◽  
Leatherside Chub

ABSTRACT Outside of anadromous salmonids and a few endangered species, the biology of native freshwater fishes of western North America is poorly known. What do we need to know to effectively manage native species and avoid decline and extinction? A recent analysis of the role of science in the Pacific salmon controversy outlines a clear framework for biological evaluation and management of native species. This framework has three components: (1) determine the status of populations based on genetic and ecological variation, (2) identify and quantify threats to populations, and (3) determine actions to alleviate threats and promote conservation of populations.We use our studies of leatherside chub <em>Gila copei</em> (also known as <em>Snyderichthys copei</em>), a small cyprinid native to the Bonneville basin and upper Snake River drainage, as a case study to illustrate the application of this research and management framework. Recent surveys have revealed dramatic reductions in range of leatherside chub over the last 50 years. Genetic, morphometric, and ecological studies all indicate that leatherside chub comprise two distinct species. Leatherside chub is threatened by both habitat degradation and introduced brown trout <em>Salmo trutta</em>, and the interaction between these two threats exacerbates negative effects.We conclude by showing how studies of leatherside chub can inform and influence management, conservation, and habitat restoration activities.

Bicarbonate modulation of glucose-9nduced biphasic insulin release by rat islets

1976 ◽  
Vol 231 (3) ◽  
pp. 713-721 ◽  
Author(s):  
JC Henquin ◽  
AE Lambert
Keyword(s):  
Insulin Release ◽  
Islet Cells ◽  
Pancreatic Beta Cell ◽  
Late Phase ◽  
Early Response ◽  
Rat Islets ◽  
Cell Functions ◽  
Biphasic Insulin Release ◽  
Two Phases

The role of HCO3 ions in pancreatic beta-cell functions was evaluated with isolated rat islets. The early phase of insulin release was absent when HCO3 ions were omitted from the medium prior to glucose stimuation, but was augmented if HCO3- withdrawal or reintroduction coincided with glucose increase. The inhibition of the late phase augmented as a function of the duration of HCO3- absence, and its reversibility upon readmission of the anion was delayed. Theophylline and cytochalasin B partially corrected the inhibition of the late phase but failed to restore a rapid response. In the presence of 5 mM NaHCO3, the early response was delayed but the total response was normal. In a HCO3--free medium, glucose oxidation and utilization and glucose transport in islet cells were unaltered. Uptake of calcium was reduced in the absence of HCO3 ions, but normal in 5 mM HCO3-. The results document the importance of HCO3- in insulin release and show that the two phases of glucose-induced secretion are differentially modified by its omission. Some of these findings may be explained by alterations in Ca++ uptake by islet cells. It is suggested that the mechanisms regulating insulin granule extrusion upon stimulation by glucose may be partially different for the two phases of release.

Inward rectification in Limulus ventral photoreceptors

1992 ◽  
Vol 8 (1) ◽  
pp. 19-25 ◽  
Author(s):  
Cynthia L. Phillips ◽  
Juan Bacigalupo ◽  
Peter M. O'Day
Keyword(s):  
Late Phase ◽  
Inward Rectifier ◽  
Inward Rectification ◽  
Voltage Range ◽  
Inward Current ◽  
Intracellular Ca ◽  
Dynamic Voltage ◽  
Inward Currents ◽  
Two Phases ◽  
Inwardly Rectifying

AbstractWe examined inward rectification in Limulus ventral photoreceptors using the two-microelectrode voltage clamp. Hyperpolarization in the dark induced an inward current whose magnitude was distinctly dependent on extracellular K+ concentration, [K+0]. The [K+0] dependence resembled the characteristic [K+0] dependence of other inward rectifiers. The inward current was not dependent on extracellular Ca2+ or Na+, and it was unaffected by intracellular injection of Cl−. The hyperpolarization induced currents had two phases, an early nearly instantaneous phase and a slowly developing late phase. The currents were sensitive to extracellular barium and cesium. In voltage-pulse experiments, the magnitudes of the inwardly rectifying currents were variable from cell to cell, with some cells exhibiting negligible inward currents. Large hyperpolarizations (to membrane potentials more negative than about – 140 mV) caused unstable inward current recordings, irreversible desensitization, and irreversible elevation of intracellular Ca2+ concentration. The inward rectifier provides negative feedback by tending to depolarize the cell (with inward current) in response to hyperpolarization. We suggest that the inward rectifier reduces the amount of hyperpolarization that would otherwise be generated by electrogenic processes. This feature would restrict the dynamic voltage range of the photoreceptors at very hyperpolarized potentials.

scholarly journals IRRIGAÇÃO LOCALIZADA POR GRAVIDADE COM MICROTUBOS

Irriga ◽  
2006 ◽  
Vol 11 (2) ◽  
pp. 266-279 ◽  
Author(s):  
Rodrigo Otávio Rodrigues de Melo Souza ◽  
Gerardo Felipe Espinoza Pérez ◽  
Tarlei Arriel Botrel
Keyword(s):  
Drip Irrigation ◽  
Irrigation System ◽  
Water Reservoir ◽  
The Other ◽  
Trickle Irrigation ◽  
Total Cost ◽  
Great Performance ◽  
Distribution Uniformity ◽  
Two Phases ◽  
The Cost

IRRIGAÇÃO LOCALIZADA POR GRAVIDADE COM MICROTUBOS  Rodrigo Otávio Rodrigues de Melo Souza; Gerardo Felipe Espinoza Pérez; Tarlei Arriel BotrelInstituto Centro Tecnológico de Ensino – CENTEC, Fortaleza, CE,  [email protected]  1 RESUMO             Os objetivos deste trabalho foram: dimensionar, implantar e avaliar um sistema de irrigação com microtubos por gravidade; e apresentar o custo do sistema com microtubos comparando-o com o custo do “kit” para irrigação localizada por gravidade, disponível no mercado. O experimento foi dividido em duas etapas, sendo que a primeira consistiu no dimensionamento, elaboração, montagem e avaliação do sistema de irrigação. A segunda etapa consistiu na implantação da cultura da alface em três canteiros, onde em dois canteiros a água foi fornecida por uma caixa d’água elevada a uma altura de1 m e distribuída para as alfaces através dos microtubos. No outro canteiro, a irrigação foi realizada através de um regador. Conforme os resultados observados o sistema obteve ótimo desempenho. Além de aplicar água com 97% de uniformidade de distribuição, também ficou provado que o microtubo foi fabricado com qualidade e uniformidade. O custo total do sistema para a irrigação de 16 canteiros ficou em R$ 466,77. A proposta de utilização do sistema de irrigação localizada com microtubos por gravidade demonstrou ser uma alternativa viável, tanto tecnicamente quanto economicamente, para os pequenos produtores. UNITERMOS: Irrigação por gotejamento, microtubos, baixa pressão  SOUZA, R.O.R. DE M.; PÉREZ, G.F.E.; BOTREL, T.A. GRAVITY TRICKLE IRRIGATION WITH MICROTUBES  2 ABSTRACT             The objectives of this study were to design, implant and evaluate a gravity irrigation system with micro tubes; and to show the cost of the system with micro tubes compared to the cost of the “kit” for gravity drip irrigation commercialized by irrigation companies. The experiment was divided into two phases: the first one consisted of the design, elaboration, assembly and evaluation of the irrigation system, whereas the second one consisted of the implantation of a lettuce culture in three flowerbeds. The water was provided by a1 mhigh water reservoir and distributed to the lettuce culture through micro tubes in two of the flowerbeds. In the other one, the irrigation occurred through a watering can. According to the results, the system achieved a great performance. Besides applying water with 97% distribution uniformity, it has also been proved that the micro tube manufacturing had quality and uniformity. The total cost of the irrigation system implementation in 16 flowerbeds was US$ 190.51. The use of gravity trickle irrigation system with micro tubes turned out to be a possible technical and economic option for small farmers. KEYWORDS: drip irrigation, low pressure, microtubes 

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