scholarly journals A Cone Fishway Facilitates Lateral Migrations of Tropical River-Floodplain Fish Communities

Water ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 513
Author(s):  
Lee J. Baumgartner ◽  
Craig Boys ◽  
Tim Marsden ◽  
Jarrod McPherson ◽  
Nathan Ning ◽  
...  

Fisheries in many tropical river-floodplain systems are under threat from physical obstructions caused by ongoing river infrastructure development. There is a growing need for innovative, cost-effective technologies to mitigate the impacts of these obstructions. This study examined the effectiveness of a new cone fishway for facilitating lateral migrations of river-floodplain fish communities in the Lower Mekong Basin in Lao PDR. We assessed the species richness, size range, abundance and biomass of fish able to pass through a cone fishway, using paired entrance and exit sampling during both dawn/day and dusk/night. Overall, a diverse range of taxa (76 species) and size classes (25–370 mm) ascended the cone fishway. The total size range of fishes observed at the fishway entrance was similar to that at the exit, although the fish at the entrance were significantly smaller (in length) than those at the exit, during both diel periods. Additionally, there were significantly higher abundances of fish at the entrance than at the exit, but there was no difference in total biomass, again for both periods. These results suggest that, with further development, the cone fishway design has considerable potential for facilitating the lateral migrations of diverse tropical river-floodplain fish communities at low/medium head infrastructure.

Hydrobiologia ◽  
2021 ◽  
Vol 848 (9) ◽  
pp. 2043-2053 ◽  
Author(s):  
Vanessa Ernandes de Amo ◽  
Jéssica Ernandes-Silva ◽  
Dieison André Moi ◽  
Roger Paulo Mormul

Author(s):  
Harish C. Upadhyay

: No doubt antibiotics have saved billions of lives, but lack of novel antibiotics, development of resistance mechanisms in almost all clinical isolates of bacteria, and recurrent infections caused by persistent bacteria hamper the successful treatment of infections. Due to widespread emergence of resistance, even the new families of antimicrobial agents have a short life expectancy. Drugs acting on single target often lead to drug resistance and are associated with various side effects. To overcome this problem either multidrug therapy or single drug acting on multiple targets may be used. The later are called ‘hybrid molecules’ which are formed by clubbing two biologically active pharmacophores together with or without an appropriate linker. In this rapidly evolving era, the development of natural product-based hybrid molecules may be a super-alternative to multidrug therapy to combat drug resistance caused by various bacterial and fungal strains. Coumarins (benzopyran-2-one) are one of the earliest reported plant secondary metabolites having clinically proven diverse range of pharmacological properties. On the other hand, 1,2,3-triazole is a common pharmacophore in many drugs responsible for polar interactions improving the solubility and binding affinity to biomolecular targets. In this review we discuss recent advances in Coumarin-1,2,3-triazole hybrids as potential antibacterial agents aiming to provide a useful platform for the exploration of new leads with broader spectrum, more effectiveness, less toxicity with multiple modes of action for the development of cost-effective and safer drugs in the future.


2017 ◽  
Vol 5 (2) ◽  
pp. 21-24
Author(s):  
Lucia Možuchová ◽  
◽  
Lucia Gašperová ◽  
Mária Rostášová ◽  
Dorota Jelonek

The university is an important part of the region's infrastructure and has the potential to initiate changes and transform the economy into a diverse range. The presence of a university in a host city or region has a strong impact on regional development. Universities are usually among the largest employers in the city. Their employees, students and visitors spend some of their finances in this city, which have an impact on local and regional economic development. The total size of the impact of university varies depending on the size of the university and the characteristics of the local and regional economy. The primary aim of the contribution is identification of the selected short-term impacts of the University of Žilina to the city and region, where it has its registered office. To achieve the stated goal, primary research was carried out primarily focused on the economic impact of university staff on the development of the Žilina´s region.


Author(s):  
Doudou Nanitamo Luta ◽  
Atanda K. Raji

Hydrogen is likely to play a significant role in the concept of low-carbon power generation in support to renewable energy systems. It is abundant, eco-friendly, highly efficient and have the potential to be more cost-effective than fossil fuels provided that the engineering challenges associated with its safe infrastructure development, economical extraction and storage are solved. Presently, about 50 million metric tons of hydrogen is generated on a yearly basis, most of that is used for oil refining and ammoniac production. Other applications include electric vehicles, power to gas and power generation, etc. This study focuses on the use of hydrogen for power generation. The main goal is to investigate technical and economic performances of a renewable hydrogen-based energy system as an alternative to diesel generators for powering a remote telecoms base station. The proposed energy system consists of a photovoltaic generator, an electrolyser, a fuel cell, a hydrogen tank, a battery storage system and a power-conditioning unit. The system is simulated using Homer Pro software.


2017 ◽  
Vol 17 (2) ◽  
pp. 769-791 ◽  
Author(s):  
Athanasios Tsikerdekis ◽  
Prodromos Zanis ◽  
Allison L. Steiner ◽  
Fabien Solmon ◽  
Vassilis Amiridis ◽  
...  

Abstract. We investigate the sensitivity of aerosol representation in the regional climate model RegCM4 for two dust parameterizations for the period 2007–2014 over the Sahara and the Mediterranean. We apply two discretization methods of the dust size distribution keeping the total mass constant: (1) the default RegCM4 4-bin approach, where the size range of each bin is calculated using an equal, logarithmic separation of the total size range of dust, using the diameter of dust particles, and (2) a newly implemented 12-bin approach with each bin defined according to an isogradient method where the size ranges are dependent on the dry deposition velocity of dust particles. Increasing the number of transported dust size bins theoretically improves the representation of the physical properties of dust particles within the same size bin. Thus, more size bins improve the simulation of atmospheric processes. The radiative effects of dust over the area are discussed and evaluated with the CALIPSO dust optical depth (DOD). This study is among the first studies evaluating the vertical profile of simulated dust with a pure dust product. Reanalysis winds from ERA-Interim and the total precipitation flux from the Climate Research Unit (CRU) observational gridded database are used to evaluate and explain the discrepancies between model and observations. The new dust binning approach increases the dust column burden by 4 and 3 % for fine and coarse particles, respectively, which increases DOD by 10 % over the desert and the Mediterranean. Consequently, negative shortwave radiative forcing (RF) is enhanced by more than 10 % at the top of the atmosphere and by 1 to 5 % on the surface. Positive longwave RF locally increases by more than 0.1 W m−2 in a large portion of the Sahara, the northern part of the Arabian Peninsula and the Middle East. The four-bin isolog method is to some extent numerically efficient, nevertheless our work highlights that the simplified representation of the four-bin approach produces less dust optical depth and RF, a fact that should be taken into account by future studies of the same region.


Author(s):  
Emil A. Maschner ◽  
Basel Abdalla

The subject of lateral buckling design in recent years has by necessity become increasingly more involved as pipeline projects have moved into more difficult environments where there is a need for optimized economic solutions with assured through-life reliability. The authors have had direct design responsibility and specialist involvement with a large number of projects covering a diverse range of environments, single or PIP systems, variable product characteristics and operating conditions, external applied loading type, and geographical installation limitations. These include shallow and deep water, large thin walled and small thick walled diameter pipes, flat to undulating hard to soft seabed, variable cohesive and non-cohesive surficial soil types and various other project considerations which have impacted on the chosen design solution. The purpose of this paper will be to highlight aspects of global buckling design associated with reliable in place systems and conversely those aspects associated with integrity risks to the as-laid operational pipelines. A review of past project challenges along with a commentary as to the state of the art at the time gives an opportunity to evaluate risks and challenges being faced on current projects. Particularly, as it seeks to develop ever more cost effective designs with proven robustness but optimized safety margins for the installation and operation of HT/HP pipelines in marginal fields.


2008 ◽  
Vol 1 ◽  
pp. 43-49
Author(s):  
Krishna Kanta Panthi

Being topographically steep and consisting of many rivers originating from the glaciers of the Himalaya, Nepal is gifted in water resources. As a developing country, Nepal needs to accelerate to develop its crucial infrastructures for the economic prosperity of the nation. This is achievable by developing the enormous hydropower potential available, making short and efficient roads through the steep mountain topography, extracting mines for various purposes, and providing cost effective solutions for the storage facilities. These developments are not possible unless tunnels and underground caverns are used. Due to tectonic activity, however, the rock mass in Nepal and across the Himalayan region is somewhat different in their engineering behaviour. These differences in mechanical behaviour are mainly caused by a high degree of folding, faulting, shearing, fracturing and deep weathering. As a result, severe instability problems associated with this complex geological setup have to be faced during tunnelling. This is the major challenge to be addressed in a scientific manner in order to make tunnel option more cost effective, feasible and safer. This paper delineates the possible areas where tunnels and underground caverns are needed and may play an important role in the socio-economic development of the nation, discusses the major geological challenges faced while tunnelling, and briefly describes methodologies to be used for analysing geological uncertainties. Key words: Himalayan geology, tunnelling, Nepal Hydro Nepal: Journal of Water, Energy and Environment Vol. I, Issue No. 1 (2007) pp. 43-49


Author(s):  
Shruti Tyagi

Objective: This study demonstates  a simple, cost effective protocol  for biosynthesis of stable silver (Ag) and gold (Au) nanoparticles from Hibiscus Rosa sinesis and their comparison by applying antibacterial activities against nine pathogenic bacterial species.Methods: Silver (Ag) and gold (Au) nanoparticles were biosynthesized from Hibiscus Rosa sinesis were characterized by UV–VIS spectroscopy, FTIR and TEM. The antibacterial activities  of AgNPs  and AuNPs were evaluated against  9 pathogenic bacterial species  Pseudomonas aeroginosa, Bacillus subtilis Micrococcus luteus, Staphylococcus aureus, Staphylococcus epidermidis, Enterobacter aerogens, Escherichia coli, Streptococcus pneumoniae, Aeromonas hydrophila by the agar disc diffusion method.Results: Synthesized AgNPs  were obtained in 13.01 to 28.14 nm size range, while AuNPs were in  6.32 to 18.19 nm size range. The results of Fourier transform infrared spectroscopy (FTIR) spectra indicates  that the AuNPs are bound to amine groups and the AgNPs to carboxylate ion groups. The antibacterial activities  of AgNPs,  the zone of inhibition significantly increased with the  increases of concentrations of AgNPs in all pathogenic bacterial species  except  in the case of S. epidermidis at 50%, S. aerogenes and A. hydrophila at 70%, while in case of AuNPs antibacterial activity  was displayed  only against B. subtilis at 20% and 100% concentration.Conclusion: This study suggests that AgNPs exhibits outstanding antibacterial activity against pathogenic bacteria as compared to AuNPs synthesized from Hibiscus Rosa sinensis leaf extract and insights to their potential applicability as an alternative antibacterial  agent in microbial and human health system to reduce the resistance ability of pathogenic bacteria. Keywords: silver nanoparticles; gold  nanoparticles; UV–VIS spectroscopy; FTIR; TEM; antibacterial activities.  


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