scholarly journals Fish passages in South America: an overview of studied facilities and research effort

2017 ◽  
Vol 15 (2) ◽  
Author(s):  
Nibelle A. Lira ◽  
Paulo S. Pompeu ◽  
Carlos S. Agostinho ◽  
Angelo A. Agostinho ◽  
Marlene Sofia Arcifa ◽  
...  
Keyword(s):  
South America ◽  
Scientific Literature ◽  
Research Effort ◽  
Fish Passage ◽  
River Regulation ◽  
Management Tool ◽  
Fish Migration ◽  
The Past ◽  
Fluvial Ecosystems ◽  
Conservation And Management

ABSTRACT River regulation has fragmented fluvial ecosystems in South America, affecting fish migration and dispersion dynamics. In response, authorities have installed fish passage facilities (FPF) to mitigate impacts. However, little is known about the geographical distribution of these facilities, and no synthesis of the research effort applied to understanding their functioning and limitations exists. To address this issue, our study gathered the available scientific literature about fishways in South America to provide an overview of studied FPF and associated research effort. We found 80 studies that investigated 25 FPF, mostly ladders installed in the upper reaches of large rivers, particularly in the Paraná River Basin. One important finding is that most facilities do not lead to upstream and/or downstream sites due to the presence of other dams with no FPF. Though the number of studies has increased over the past 10 years, there is no consistent trend towards increased research effort. Overall, studies have focused on the fishway itself (i.e. upstream passage), and rarely evaluated broader issues (i.e. habitat distribution, population dynamics, conservation and management success). Our research therefore identified technical limitations of past studies, and revealed important gaps in the knowledge of FPF as a management tool.

A 200-Year History of the Study of Childhood Language Disorders of Unknown Origin: Changes in Terminology

2020 ◽  
Vol 5 (1) ◽  
pp. 6-11 ◽  
Author(s):  
Laurence B. Leonard
Keyword(s):  
Language Impairment ◽  
Specific Language Impairment ◽  
Scientific Literature ◽  
Language Disorder ◽  
Language Disorders ◽  
Unknown Origin ◽  
Developmental Language Disorder ◽  
The Past ◽  
History Of ◽  
The Many

Purpose The current “specific language impairment” and “developmental language disorder” discussion might lead to important changes in how we refer to children with language disorders of unknown origin. The field has seen other changes in terminology. This article reviews many of these changes. Method A literature review of previous clinical labels was conducted, and possible reasons for the changes in labels were identified. Results References to children with significant yet unexplained deficits in language ability have been part of the scientific literature since, at least, the early 1800s. Terms have changed from those with a neurological emphasis to those that do not imply a cause for the language disorder. Diagnostic criteria have become more explicit but have become, at certain points, too narrow to represent the wider range of children with language disorders of unknown origin. Conclusions The field was not well served by the many changes in terminology that have transpired in the past. A new label at this point must be accompanied by strong efforts to recruit its adoption by clinical speech-language pathologists and the general public.

IV.—The Geological Development, Descent and Distribution of the Mammalia

1893 ◽  
Vol 10 (9) ◽  
pp. 401-412 ◽  
Author(s):  
Karl A. von Zittel
Keyword(s):  
South America ◽  
The Past ◽  
Limited Experience ◽  
The World ◽  
Relationship Of ◽  
North And South America ◽  
The Relationship ◽  
North And South ◽  
Animal World

In a spirited treatise on the ‘Origin of our Animal World’ Prof. L. Rütimeyer, in the year 1867, described the geological development and distribution of the mammalia, and the relationship of the different faunas of the past with each other and with that now existing. Although, since the appearance of that masterly sketch the palæontological material has been, at least, doubled through new discoveries in Europe and more especially in North and South America, this unexpected increase has in most instances only served as a confirmation of the views which Rutimeyer advanced on more limited experience. At present, Africa forms the only great gap in our knowledge of the fossil mammalia; all the remaining parts of the world can show materials more or less abundantly, from which the course followed by the mammalia in their geological development can be traced with approximate certainty.

scholarly journals Unprecedented Coordination-Induced Bright Red Emission from Group 12 Metal-Bound Triarylazoimidazoles

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1739
Author(s):  
Artyom A. Astafiev ◽  
Olga V. Repina ◽  
Boris S. Tupertsev ◽  
Alexey A. Nazarov ◽  
Maria R. Gonchar ◽  
...  
Keyword(s):  
Visible Light ◽  
Metal Complexes ◽  
Scientific Literature ◽  
Photo Luminescence ◽  
Red Emission ◽  
The Past ◽  
Highly Efficient ◽  
Luminescence Emission ◽  
New Family ◽  
Group 12

Arylazoimidazoles are important dyes which were intensively studied in the past. In contrast, triarylazoimidazoles (derivatives which carry aryl substituents at the imidazole core) received almost no attention in the scientific literature. Here, we report a new family of simple and easily accessible triarylazoimidazole-group 12 metal complexes, which feature highly efficient photo-luminescence emission (Φ up to  0.44). Novel compounds exhibit bright red emission in solution, which could be excited with a visible light.

scholarly journals Analgesia for Sheep in Commercial Production: Where to Next?

Animals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 1127
Author(s):  
Alison Small ◽  
Andrew David Fisher ◽  
Caroline Lee ◽  
Ian Colditz
Keyword(s):  
Research Effort ◽  
Mitigation Strategies ◽  
Worth Living ◽  
Life Worth Living ◽  
The Past ◽  
Considerable Research ◽  
Husbandry Practices ◽  
Industry Practice ◽  
Successful Launch ◽  
Inflammatory Drugs

Increasing societal and customer pressure to provide animals with ‘a life worth living’ continues to apply pressure on livestock production industries to alleviate pain associated with husbandry practices, injury and illness. Over the past 15–20 years, there has been considerable research effort to understand and develop mitigation strategies for painful husbandry procedures in sheep, leading to the successful launch of analgesic approaches specific to sheep in a number of countries. However, even with multi-modal approaches to analgesia, using both local anaesthetic and non-steroidal anti-inflammatory drugs (NSAID), pain is not obliterated, and the challenge of pain mitigation and phasing out of painful husbandry practices remains. It is timely to review and reflect on progress to date in order to strategically focus on the most important challenges, and the avenues which offer the greatest potential to be incorporated into industry practice in a process of continuous improvement. A structured, systematic literature search was carried out, incorporating peer-reviewed scientific literature in the period 2000–2019. An enormous volume of research is underway, testament to the fact that we have not solved the pain and analgesia challenge for any species, including our own. This review has highlighted a number of potential areas for further research.

On the use of leading safety indicators in maritime and their feasibility for Maritime Autonomous Surface Ships

2021 ◽  
pp. 1748006X2110276
Author(s):  
Krzysztof Wróbel ◽  
Mateusz Gil ◽  
Przemysław Krata ◽  
Karol Olszewski ◽  
Jakub Montewka
Keyword(s):  
Literature Review ◽  
Current Practice ◽  
Scientific Literature ◽  
Research Effort ◽  
Holistic Approach ◽  
Research Directions ◽  
Safety Critical ◽  
Intact Stability ◽  
Conference Papers ◽  
Operational Aspects

Although the safety of prospective Maritime Autonomous Surface Ships will largely depend on their ability to detect potential hazards and react to them, the contemporary scientific literature lacks the analysis of how to achieve this. This could be achieved through an application of leading safety indicators. The aim of the performed study was to identify the research directions of leading safety indicators in three safety-critical operational aspects of Maritime Autonomous Surface Ships: collision avoidance, intact stability, and communication. To achieve this, literature review is performed, taking into account scientific documents including journal and conference papers. The results indicate that the need for establishing operational leading safety indicators is recognized by numerous scholars, who sometimes make suggestions of what the set of indicators shall consist of. Some leading safety indicators for autonomous vessels are readily identifiable in the scientific literature and used in current practice. However, the research effort is lacking a holistic approach to the issue.

scholarly journals Turning Pools in Stepped Fishways: Biological Assessment via Fish Response and CFD Models

Water ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1186
Author(s):  
Francisco Javier Bravo-Córdoba ◽  
Juan Francisco Fuentes-Pérez ◽  
Jorge Valbuena-Castro ◽  
Andrés Martínez de Azagra-Paredes ◽  
Francisco Javier Sanz-Ronda
Keyword(s):  
3D Models ◽  
Fish Passage ◽  
Biological Assessment ◽  
Fish Migration ◽  
Longitudinal Development ◽  
Passive Integrated Transponder ◽  
Design Component ◽  
Cfd Models ◽  
Vertical Slot ◽  
Fish Response

With the aim of building more compact fishways and adapting them to field conditions to improve their location by fish, it is common to use turning pools, reducing the longitudinal development of the construction. However, depending on their design, turning pools may affect the hydraulic performance of the fishway and consequently the fish passage. To study these phenomena, turning pools in a vertical slot and in different configurations of submerged notches with bottom orifice fishway types were assessed. Both types of fishways were studied using numerical 3D models via OpenFOAM, a computational fluid dynamics software, in combination with fish responses, assessed with PIT (Passive Integrated Transponder) tag telemetry for three different species of potamodromous cyprinids in several fishways. Results show differences between the hydrodynamics of straight and turning pools, with lower values in the hydrodynamic variables in turning pools. Regarding fish behavior, the ascent was slower in turning pools but with no effect on passage success and without being a problem for fish migration. This information validates the use of turning pools as a key design component for fishways for studied species.

Explosive Removal of Concrete From Reinforced Walls

2007 ◽  
Author(s):  
Denis D. Rickman ◽  
John Q. Ehrgott ◽  
Stephen A. Akers ◽  
Jon E. Windham ◽  
Dennis W. Moore
Keyword(s):  
Explosive Charge ◽  
Research Effort ◽  
Us Army ◽  
Steel Reinforced Concrete ◽  
The Past ◽  
The Us ◽  
Development Center ◽  
The Relationship ◽  
Improved Methods ◽  
Combat Environment

During the past several years, the US Army has focused considerable attention toward developing improved methods for breaching walls in the urban combat environment. A major thrust area is centered on finding improved methods to breach the toughest wall type that Army units are likely to face: a double (steel) reinforced concrete (RC) wall. One impediment to this effort is that the relationship between the contact explosive charge configuration and the quantity of concrete removed has not been thoroughly understood. The U.S. Army Engineer Research and Development Center has conducted a research effort to better define the effectiveness of various explosive charge configurations in breaching RC walls. This paper presents a discussion of results from this research.

scholarly journals Implementing new northernmost records to modelling the distribution of Hypsiboas caingua (Anura: Hylidae) in South America

2014 ◽  
Vol 74 (4) ◽  
pp. 854-860 ◽  
Author(s):  
M Delatorre ◽  
TS Vasconcelos ◽  
NL Cunha ◽  
FI Martins ◽  
FH Oda ◽  
...  
Keyword(s):  
South America ◽  
Geographic Distribution ◽  
Scientific Literature ◽  
Climatic Data ◽  
Distribution Models ◽  
Distribution Modelling ◽  
Field Surveys ◽  
Linear Distance ◽  
New Localities ◽  
Evolutionary Aspects

New northwestern records of the striped treefrog Hypsiboas caingua (Carrizo, 1991 “1990”) are presented for Brazil, extending its known geographic distribution approximately 115 km northward (linear distance) of the previous northernmost record of the species. In all new localities, individuals of H. caingua were only found in calling activity under temperatures below 18°C. The species appears to be associated with Atlantic Forest, although it had already been recorded in Cerrado. Although the scientific literature data suggests that H. caingua presents discontinuous geographical distribution, three methods of distribution modelling based on climatic data show that the species' distribution is continuous. The gap in the distribution may be related to the lack of field surveys in the regions that connect these populations, especially in colder periods. Nevertheless, factors other than climate might also be responsible for the current distribution of H. caingua, since the species was absent in well-surveyed sites situated between the areas of modeled distribution. Therefore, further studies on natural history, populations' genetic structure, and geographic distribution models implementing factors other than climate will be important to elucidate some ecological and evolutionary aspects of the distribution of H. caingua in South America.

scholarly journals A 21st Century Vision for Neotropical Snake Systematics

2018 ◽  
Vol 1 (1) ◽  
pp. 58
Author(s):  
Robert Alexander Pyron
Keyword(s):  
Species Richness ◽  
Natural History ◽  
Global Change ◽  
South America ◽  
Ecosystem Function ◽  
Museum Specimens ◽  
Fine Grained ◽  
The Past ◽  
The Caribbean ◽  
Recent Synthesis

We live in an unprecedented age for systematics and biodiversity studies. Ongoing global change is leading to a future with reduced species richness and ecosystem function (Pereira, Navarro, & Martins, 2012). Yet, we know more about biodiversity now than at any time in the past. For squamates in particular, we have range maps for all species (Roll et al., 2017), phylogenies containing estimates for all species (Tonini, Beard, Ferreira, Jetz, & Pyron, 2016), and myriad ecological and natural-history datasets for a large percentage of species (Meiri et al., 2013; Mesquita et al., 2016). For neotropical snakes, a recent synthesis of museum specimens and verified localities offers a fine-grained perspective on their ecogeographic distribution in Central and South America, and the Caribbean (Guedes et al., 2018).

scholarly journals From Planning to Action: Forest Conservation and Management in Papua New Guinea

2000 ◽  
Vol 6 (4) ◽  
pp. 277 ◽  
Author(s):  
Kathy MacKinnon
Keyword(s):  
Papua New Guinea ◽  
Large Scale ◽  
Forest Conservation ◽  
Forest Products ◽  
New Guinea ◽  
Subsistence Agriculture ◽  
The Past ◽  
Language Groups ◽  
Eastern Half ◽  
Conservation And Management

Papua New Guinea (PNG) occupies the eastern half of the island of New Guinea and still boasts 33 million hectares of closed natural forest (77% of the country), home to numerous endemic species. Overall PNG is sparsely populated with some 700 distinct cultural/ language groups. Economic growth over the past two decades has been spurred by large-scale mining, petroleum and logging operations though the majority of the population continues to rely upon subsistence agriculture (swidden) and collection and utilization of forest products. Some 15 million hectares of forests are accessible for logging, of which 1.5 million hectares have already been logged, generally in an unsustainable manner. Of the over 6 million ha of approved timber blocks more than 1.5 million hectares have been located in areas of high biological value. Forest loss and degradation is now becoming a serious problem.

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