scholarly journals EVALUACIÓN DE LOS RIESGOS DE AFECTACIÓN POR EL ESTABLECIMIENTO DE GRANJAS ATUNERAS EN RELACIÓN CON LA DISTRIBUCIÓN ESPACIAL DE CETÁCEOS EN EL GOLFO DULCE, COSTA RICA

2011 ◽  
Vol 1 ◽  
pp. 159 ◽  
Author(s):  
Lenin E. Oviedo Correa ◽  
Juan Diego Pacheco ◽  
David Herra Miranda

Este estudio trata sobre la distribución espacial de depredadores marinos topes, particularmente cetáceos odontocetos y misticetos migratorios. Se describe el riesgo potencial de afectación por el establecimiento de instalaciones asociadas con operaciones locales de maricultura: jaulas de engorde para atún. Por medio de un enfoque teórico y empírico se establece cuantitativamente como la profundidad máxima, un factor limitante en la distribución y definición del nicho ecológico de cetáceos, se solaparía en valores con el área propuesta para el establecimiento de las jaulas, lo que induciría dos escenarios probables de afectación: el desplazamiento de las poblaciones de depredadores de un hábitat-nicho de alimentación potencial y la interacción progresiva entre los depredadores con la fauna acompañante alrededor de las instalaciones de la operación de cultivo, lo anterior implicaría un riesgo perenne de captura incidental de dichos depredadores. Adicionalmente, la presencia de ballenas jorobadas durante la temporada de lluvia en zonas aledañas a Punta Banco, se asociaría a una ruta migratoria desde las zonas de alimentación en Sudamérica-Antártica, que pasaría por el área proyectada para el establecimiento de la operación de maricultura. Los resultados ilustran la necesidad de seguir un principio precautorio y promover la reubicación de proyecto de maricultura en áreas de menor valor en términos de biodiversidad marina.This contribution deals with the spatial distribution of marine top predators, particularly odontocete and migratory misticete cetaceans. The study describes the potential risk of disturbances due to the establishment of mariculture operations and corresponding infrastructure: tuna feed lots. Through a mixed theoretical and empirical approach, this research corroborates how the maximum depth, a limiting factor in the definition of cetacean trophic niches off the study area, overlaps with the values for depths from an area proposed as the focal location of a tuna feed lot facility. The latter implies two particular scenarios: the translocation of the local predator population from a potential foraging habitat-niche, and the progressive negative interaction between predators and the accompanying fish fauna around of the cages, with a high probability of incidental capture of those predators by entanglement. Additionally, the occurrence of humpback whales during the rainy season associated with a migratory route from feeding grounds off Chile-Antarctica, that would pass through the area projected to harbor the mariculture operation. The results illustrate the need of considering a precautionary approach and relocate mariculture projects to areas of lesser value in terms of marine biodiversity.

2018 ◽  
pp. 31-35
Author(s):  
Ya. Serikov

Ensuring the reliability of buildings, structures, analysis of their structural elements during reconstruction or major repair includes the task of determining the physical and mechanical characteristics of materials — strength, homogeneity, evaluation of structural heterogeneity, the presence of microcracks, etc. In solving this problem, an ultrasonic pulse method of non-destructive quality control is used. The basis of the method is the dependence of the parameters of ultrasonic oscillations, on these characteristics when they pass through the material. As the main parameter of the information ultrasonic signal, the time of its passage from the radiating to the receiving ultrasonic transducers is used. The amplitude of the information ultrasonic signal to a large extent depends on the structure of the investigated material, its acoustic resistance. At significant violations of the structure of the material there is a significant decrease in the amplitude of the information signal, which causes an increase in the error of measuring the time of its passage, and hence the definition of characteristics, quality of the investigated material. The article describes the developed method of increasing the accuracy of measuring the time of passage of the ultrasonic signal from the radiating to the receiving ultrasonic transducers. The essence of the technique is to use the mathematical modeling of the shape of the ultrasound signal, in particular the form of its so-called «first introduction».


2021 ◽  
Vol 2 ◽  
pp. 187-193
Author(s):  
Tarjoko Tarjoko ◽  
Mujiono Mujiono

Pest attacks on chili plants are the main limiting factor in cultivation activities. The research  aims to determine the effect of single application of botanical pesticide maja-gadung (PMG), single application of secondary metabolite Beauveria bassiana BIO (BIO B10), combined application of PMG and BIO B10  on pest populations, predator populations and plant growth and production of  chili. The  reesearh used a factorial Completely Randomized Block Design (RAKL) with 3 replications, so there were 9 treatment combinations (0 ml/l PMG, 4 ml/l PMG, 8 ml/l BIO B10, 0 ml/l PMG, 2  ml/l BIO B10,  4 ml/l BIO B10, 4 ml PMG+2 ml/l BIO B10,  4 ml/ml PMG+4 ml BIO B10, 8 ml/l  PMG+2ml/l BIO B10, 8 ml/l PMG+4 ml/l BIO B10). The variables observed were Thrips sp population, predator population, plant height, number of leaves, and fruit weight per plant. The results showed that the single application treatment of PMG  with a concentration of 4 ml/l and 8 ml/l was able to suppress the population of Thrips sp. by 21.6% and 41.4% compared to the control. The single application treatment of BIO B10  with concentrations of 2 ml/l and 4 ml/l was able to suppress the population of Thrips sp. by 66.5% and 65.5% compared to the control. The best combination application is PMG  and BIO B10with a concentration of 8 ml/l + 4 ml/l which is able to suppress the population of Thrips sp. by 76.9% compared to the control. The application treatment of PMG andBIO B10 did not affect plant height, number of leaves, and fruit weight per plant.


2008 ◽  
Vol 19 (1) ◽  
pp. 383-391
Author(s):  
Julia Siboni
Keyword(s):  

Throughout his oeuvre, Beckett wavers between "unspoken words" and murmurous silences questioning in this manner the nature of the existence of "true silence." The tension between these two poles reflects the perpetual (re)construction, (re)definition of an inside and outside, interiority and exteriority. Indeed, the limit between these two spaces turns out to be more often than not mobile and porous, letting sound pass through. Thus the Beckettian subject is called on to search for a place in this profoundly dynamic space of tension, which is both limit and border and the ground of a precarious and elusive identity.


1978 ◽  
Vol 1 (16) ◽  
pp. 30 ◽  
Author(s):  
D.H. Peregrine ◽  
I.A. Svendsen

On gently sloping beaches, almost all water waves break. After the initial breaking the water motion usually appears quite chaotic. However, for a moderate time, for example two or three times the descent time of the "plunge" in a plunging breaker, the flow can be relatively well organised despite the superficial view which is largely of spray and bubbles. If waves continue to break the breaking motion, or "white water" soon becomes fully turbulent and the mean motions become quasisteady. A reasonable definition of a quasi-steady wave is one which changes little during the time a water particle takes to pass through it. We exclude water particles which may become trapped in a surface roller and surf along with the wave. At this stage in its development a wave on a beach may be described as a spilling breaker or as a bore. In fact, there is a range of these waves from those with a little white water at the crest to examples where the whole front of the wave is fully turbulent. In investigating the properties of such waves it is desirable to start by looking at the whole range of related motions. The most obvious extension is to the hydraulic jump; since, in the simplest view, it is equivalent to a bore but in a frame of reference moving with the wave. It is also an example where the mean flow is steady rather than quasisteady.


2018 ◽  
Author(s):  
Glen Smith ◽  
Ruth E Brennan

Marine spatial planning (MSP) is the dominant management tool for marine environments around the world and is an attempt to move beyond the sectoral governance of marine spaces. Scotland is no exception and MSP is central to its management plans. The interpretation and use of spatial data informs these plans and maps provide the backbone of the decision-making process. Whilst not refuting MSP as a governance tool, this paper examines more closely some of the inherent problems with representing marine environments spatially and how the practice of map-making inevitably interacts with social-ecological networks. Borrowing from critical cartography and Actor-Network Theory (ANT), four observations are made: 1) due to the necessary procedure of categorising and simplifying data, maps do not always accurately represent changeable marine environments and situations; 2) maps can produce reality as much as represent it; 3) mapping has become the point through which all actors and stakeholders must pass; 4) as they are obliged to pass through this point, the roles and definition of certain actors can change. This discussion of marine spatial planning in Scotland demonstrates what can be learnt from viewing marine spaces as a tightly coupled social-ecological environment.


2009 ◽  
Vol 5 (H15) ◽  
pp. 532-532
Author(s):  
Hans Ulrich Käufl ◽  
Florian Kerber ◽  
Bernhard Aringer

VISIR, the VLT Imager and Spectrograph for the Mid-Infrared is a multi-mode instrument, featuring also a high resolution Echelle spectrograph with a spectral resolving power $\frac{\nu}{\Delta \nu}$ of ≈30 000 or 10 km s−1 at ν ≈ 30 000 GHz (λ ≈ 10 μm). A limited long-slit mode as well as a general cross-dispersed mode are available. The Echelle grating is illuminated with a 200 mm diameter collimated beam. Cross-dispersion is achieved by a pair of grisms in the pre-slit optics. The entire frequency interval corresponding to the “10 μ m-window” from 22 400 to 39 500 GHz is fully accessible, albeit sequentially. This interval contains a multitude of fundamental molecular rotational-vibrational bands such as SiO, OH−, H2O, NH3, CH4 and many other hydro-carbonates. Since its commissioning in April 2004, VISIR has been plagued by artifacts introduced from its detector. The cross-dispersed mode is especially handicapped, as it is the most demanding mode for dynamic range of illumination. Now an ambitious upgrade with a pair of newly developed 1k2 As:Si detectors is underway, which will fully resurrect the spectroscopic mode. This will also increase the frequency interval accessible in one exposure by 240% while changing from critical to 3-pixel sampling. Even in the absence of extra spectral features this increase is quite valuable for absorption line spectroscopy, as the limiting factor in analysis often is the definition of the photospheric continuum.


2020 ◽  
Vol 26 (4) ◽  
pp. 378
Author(s):  
Shotaro Nakagun ◽  
Laetitia I. Smoll ◽  
Takayuki Sato ◽  
Cynthia A. A. Layusa ◽  
Jo Marie V. Acebes

Humpback whales (Megaptera novaeangliae) in the western North Pacific breed in the Philippines and Japan, where there is relatively little scientific data available, leading to uncertainty about their population status and structure. This study investigates links between humpback whale populations in northern Philippines and Ogasawara, Japan, through a comparison of the most recent fluke identification catalogues. The Philippines catalogue (1999–2016) included 234 individuals, and the Ogasawara catalogue (1987–2014), 1389 individuals. The number of matched individuals was 86 (including 14 known females and 40 known males), corresponding to 36.8% of the Philippines and 6.2% of the Ogasawara catalogues. The findings included four within-season matches, with travel times as short as 25 days. The results suggest that a considerable portion of whales utilising Philippine waters pass through and also utilise the Ogasawara region, but the majority of whales found off Ogasawara either stay in that location, move to different breeding grounds, or remain out of the sampling area. Nevertheless, in light of the high site fidelity of individuals in the Philippines and Ogasawara area, as well as constant evidence of breeding activities, these regions are of importance to the lesser known western North Pacific subpopulation. Humpback whales migrating to this part of the world are estimated to be in relatively low abundance, therefore continued conservation attention is needed.


2007 ◽  
Vol 7 ◽  
pp. 221-228
Author(s):  
Paul Sturges

Campaigners against corruption advocate transparency as a fundamental condition for its prevention. Trans-parency in itself is not the most important thing: it is the accountability that it makes possible. Transparency itself is, in fact, a metaphor based on the ability of light to pass through a solid, but transparent, medium and reveal what is on the other side. In practice it allows the revelation of what otherwise might have been concealed, and it is applied in a social context to the revelation of human activity in which there is a valid public interest. It can be applied to all of those who hold power and responsibility, whether that is political or economic. More accurate definition of the term, including distinctions between open governance, procedural transparency, radical transparency, and systemic or total transparency is important. Various ways in which an observer can make use of transparency to scrutinise the activity of others, including freedom of information laws, accounting and audit systems, and the protection of public interest disclosure (whistleblowing) also need to be distinguished from each other.


Author(s):  
P. S. Sorokin ◽  

The existing approaches and regulations for the determination of the marine boundaries of the part of coastal-marine natural management are analyzed. There are no uniform boundaries in the direction toward the sea, despite the presence of numerous definitions of the coastal zone. For the purposes of maritime activities management, i.e. coastal and oceanic natural management, the geomorphological definition of the coastal zone becomes insufficient due to the greater dependence on the land space. Therefore, it is proposed to use the term "coastal-marine zone" with a broader definition, including, in addition to territorial, coastal and aquatic structures. The coastal-sea zone boundaries can be established depending on the research objectives. In our research, we suggest to establish this kind of depth boundary, considering it a limiting factor of marine economic activities.


2021 ◽  
Author(s):  
David Lecchini ◽  
Frédéric Bertucci ◽  
Lily Fogg ◽  
Camille Gache ◽  
Pascal Ung ◽  
...  

Understanding the natural state of coral reefs is paramount to evaluate the response of these ecosystems to local and global human impacts as well as management and conservation strategies. In French Polynesia, some islands are still pristine or uninhabited, such as Tupai atoll. Tupai has been uninhabited, with access to the lagoon prohibited since 2010. However, fishers from nearby islands often take from the outer reef slope at Tupai. Our marine biodiversity survey (coral, macro-invertebrates, and fish) conducted in 2019 highlighted a low density of commercial fish species and top-predators on the outer slope in comparison to the lagoon, where the top-predators represented 16% (of the density) of functional trophic groups. Our surveys also showed a high living coral cover (46%) on the outer slope of Tupai, perhaps due to the absence of both touristic sub-aquatic activities and local pollution from private and commercial activities. Overall, this initial scientific assessment of Tupai has granted an understanding of the spatial patterns of coral, macro-invertebrates, and fish assemblages in the absence of human impacts (i.e., in the lagoon), representing an ecological baseline that could inform conservation management strategies to ensure the preservation of coral reef ecosystem.


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