scholarly journals Treetop shelter of a neotropical river otter cub (Lontra longicaudis - Carnivora: Mustelidae) in an Amazonian flooded forest

2007 ◽  
Vol 37 (2) ◽  
pp. 309-312
Author(s):  
Pedro Manuel Ribeiro Simões dos Santos ◽  
Valdely Ferreira Kinupp ◽  
Alexandre Coletto-Silva

The finding of a Neotropical river otter (Lontra longicaudis) cub occupying a shelter in a hollowed treetop is reported. The observation was made in a seasonally flooded forest in Central Amazonia, during the high water peak of the annual inundation cycle. A literature review indicates that this is the first description of a shelter of the species, both in a hollowed tree and in Amazonia. This observation can indicate a strong relationship between the species' breeding cycle with the annual dynamics of Amazonian rivers. We discuss potential advantages and disadvantages of breeding when water level is high.

Forests ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 942
Author(s):  
Isabela Freitas Oliveira ◽  
Fabricio Beggiato Baccaro ◽  
Fernanda P. Werneck ◽  
Thamara Zacca ◽  
Torbjørn Haugaasen

Amazonia comprises a mosaic of contrasting habitats, with wide environmental heterogeneity at local and regional scales. In central Amazonia, upland forest (terra firme) is the predominant forest type and seasonally flooded forests inundated by white- and black-water rivers (várzea and igapó, respectively) represent around 20% of the forested areas. In this work, we took advantage of a natural spatial arrangement of the main vegetation types in central Amazonia to investigate butterfly assemblage structure in terra firme, várzea and igapó forests at the local scale. We sampled in the low- and high-water seasons, combining active and passive sampling with traps placed in both the understory and canopy. Terra firme supported the highest number of butterfly species, whereas várzea forest provided the highest number of butterfly captures. The high species richness in terra firme may reflect that this forest type is floristically richer than várzea and igapó. Várzea is a very productive environment and may thus support a higher number of butterfly individuals than terra firme and igapó. Most butterfly species (80.2%) were unique to a single forest type and 17 can be considered forest type indicator species in this landscape. Floodplain forest environments are therefore an important complement to terra firme in terms of butterfly species richness and conservation in Amazonia.


2018 ◽  
Vol 11 (2) ◽  
pp. 41-51 ◽  
Author(s):  
I. Ya. Lukasevich

The subject of the research is new tools for business financing using the initial coin offering (ICO) in the context of the development of cryptocurrencies and the blockchain technologies as their basis. The purpose of the work was to analyze the advantages and disadvantages of the ICO in comparison with traditional financial tools as well as prospects, limitations and problems of using digital financial tools. Conclusions are made in relation to possibilities, limitations and application areas of digital business financing tools, particularly in the real sector, taking into account the specifics of the Russian economy and legislation. It is shown that the main problems of using the digital financial tools are related to the economic sphere and caused by the lack of adequate approaches to evaluation of assets as well as the shortage of objective information. The problems and new tasks of corporate finance in the digital economy are defined.


2020 ◽  
Vol 26 ◽  
Author(s):  
Emir Muzurović ◽  
Zoja Stanković ◽  
Zlata Kovačević ◽  
Benida Šahmanović Škrijelj ◽  
Dimitri P Mikhailidis

: Diabetes mellitus (DM) is a chronic and complex metabolic disorder, and also an important cause of cardiovascular (CV) diseases (CVDs). Subclinical inflammation, observed in patients with type 2 DM (T2DM), cannot be considered the sole or primary cause of T2DM in the absence of classical risk factors, but it represents an important mechanism that serves as a bridge between primary causes of T2DM and its manifestation. Progress has been made in the identification of effective strategies to prevent or delay the onset of T2DM. It is important to identify those at increased risk for DM by using specific biomarkers. Inflammatory markers correlate with insulin resistance (IR) and glycoregulation in patients with DM. Also, several inflammatory markers have been shown to be useful in assessing the risk of developing DM and its complications. However, the intertwining of pathophysiological processes and the not-quite-specificity of inflammatory markers for certain clinical entities limits their practical use. In this review we consider the advantages and disadvantages of various inflammatory biomarkers of DM that have been investigated to date as well as possible future directions. Key features of such biomarkers should be high specificity, non-invasiveness and cost-effectiveness.


Crystals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 887
Author(s):  
Chunhua Feng ◽  
Buwen Cui ◽  
Haidong Ge ◽  
Yihong Huang ◽  
Wenyan Zhang ◽  
...  

Recycled aggregate is aggregate prepared from construction waste. With the development of a global economy and people’s attention to sustainable development, recycled aggregate has shown advantages in replacing natural aggregate in the production of concrete due to its environmental friendliness, low energy consumption, and low cost. Recycled aggregate exhibits high water absorption and a multi-interface transition zone, which limits its application scope. Researchers have used various methods to improve the properties of recycled aggregate, such as microbially induced calcium carbonate precipitation (MICP) technology. In this paper, the results of recent studies on the reinforcement of recycled aggregate by MICP technology are synthesized, and the factors affecting the strengthening effect of recycled aggregate are reviewed. Moreover, the strengthening mechanism, advantages and disadvantages of MICP technology are summarized. After the modified treatment, the aggregate performance is significantly improved. Regardless of whether the aggregate was used in mortar or concrete, the mechanical properties of the specimens were clearly improved. However, there are some issues regarding the application of MICP technology, such as the use of an expensive culture medium, a long modification cycle, and untargeted mineralization deposition. These difficulties need to be overcome in the future for the industrialization of regenerated aggregate materials via MICP technology.


1994 ◽  
Vol 10 (3) ◽  
pp. 399-416 ◽  
Author(s):  
Barrios E. ◽  
Herrera R.

ABSTRACTSeasonally flooded forests represent a transition between terrestrial and aquatic ecosystems. The Mapire river, a tributary of the Orinoco river, floods its surrounding forests during the wet season (May–December). The soils are very acid and the total nitrogen concentration (0.1%) is only half that found in nearby soils flooded by Orinoco waters. Ammonium-nitrogen predominates in the soil during the flooded period while nitrate-nitrogen concentrations are higher in the dry period. Wide fluctuations in the inorganic nitrogen fractions did not considerably affect the annual course of soil nitrogen.The predominance of mineralization versus nitrification (56 and 5 μgsoil month−1respectively) and possibly the synchronization of nitrogen availability with plant demand could be considered as nitrogen conserving mechanisms.In synchrony with the hydrologic cycle, the seasonally flooded forest studied shows a nitrogencycle where inputs and accumulation are maximized when the system is under minimum stress (dry season). During flooding, the system enters a period of dormancy making minimal use of nutrient and energy to avoid or tolerate anaerobiosis.


Author(s):  
A J Kinloch

When considering methods for joining materials, there are many advantages that engineering adhesives can offer, compared to the more traditional methods of joining such as bolting, brazing, welding, mechanical fasteners, etc. The advantages and disadvantages of using engineering adhesives are discussed and it is shown that it is possible to identify three distinct stages in the formation of an adhesive joint. Firstly, the adhesive initially has to be in a ‘liquid’ form so that it can readily spread over and make intimate molecular contact with the substrates. Secondly, in order for the joint to bear the loads that will be applied to it during its service life, the ‘liquid’ adhesive must now harden. In the case of adhesives used in engineering applications, the adhesive is often initially in the form of a ‘liquid’ monomer which polymerizes to give a high molecular weight polymeric adhesive. Thirdly, it must be appreciated that the load-carrying ability of the joint, and how long it will actually last, are affected by: (a) the design of the joint, (b) the manner in which loads are applied to it and (c) the environment that the joint encounters during its service life. Thus, to understand the science involved and to succeed in further developing the technology, the skills and knowledge from many different disciplines are required. Indeed, the input from surface chemists, polymer chemists and physicists, materials engineers and mechanical engineers are needed. Hence, the science and technology of adhesion and adhesives is a truly multidisciplined subject. These different disciplines have been brought together by developing a fracture mechanics approach to the failure of adhesive joints. The advances that have been made in applying the concepts of fracture mechanics to adhesive joints have enabled a better understanding of the fundamental aspects of adhesion and the more rapid extension of adhesives technology into advanced engineering applications.


2011 ◽  
Vol 1 (6) ◽  
pp. 6
Author(s):  
C. Ringe-Jorgensen

With reference to the use of high-water frequency curves, which have been suggested by Wemelsfelder as an aid to fix the maximum flooding level, an attempt will be made in the following to estimate how far certain special geographical and meteorological conditions may be expected to influence the shape of the frequency curves for different localities. The investigation concerns a particular point on the Danish North Sea coast compared with the Dutch coast, but its principles may possibly be of interest in a wider sense.


2021 ◽  
Vol 12 ◽  
Author(s):  
Yiyi Yin ◽  
Chun Wang ◽  
Dandan Xiao ◽  
Yanting Liang ◽  
Yanwei Wang

Transgenic technology is increasingly used in forest-tree breeding to overcome the disadvantages of traditional breeding methods, such as a long breeding cycle, complex cultivation environment, and complicated procedures. By introducing exogenous DNA, genes tightly related or contributed to ideal traits—including insect, disease, and herbicide resistance—were transferred into diverse forest trees, and genetically modified (GM) trees including poplars were cultivated. It is beneficial to develop new varieties of GM trees of high quality and promote the genetic improvement of forests. However, the low transformation efficiency has hampered the cultivation of GM trees and the identification of the molecular genetic mechanism in forest trees compared to annual herbaceous plants such as Oryza sativa. In this study, we reviewed advances in transgenic technology of forest trees, including the principles, advantages and disadvantages of diverse genetic transformation methods, and their application for trait improvement. The review provides insight into the establishment and improvement of genetic transformation systems for forest tree species. Challenges and perspectives pertaining to the genetic transformation of forest trees are also discussed.


Author(s):  
Kamel Karoui

With the interconnection of computers in networks, particularly through the Internet, it becomes possible to connect applications on distant computers. An application works perfectly whether it isdistant or local. Moreover, a distant applicationallows us to benefit from the following additional advantages: • Data and processes can be stored on a remote server that has a bigger storage capacity than the local host. Data can be shared between users using, for example, Remote Procedure Call (RPC), Remote Method Invocation (RMI), Java Message Service (JMS), and Enterprise JavaBeans (EJB) (Frénot, 2000): • Distant application can be used at the same time by several users; • Updating data and processes can be done only in one host; • Flexibility on distribution of the load: An application can be executed on the available machine; and • High availability: A faulty machine does not affect the others. Many approaches have been proposed and developed for communication between distant hosts on a network such as Message Passing (MP), Remote Evaluation (REV), Remote Object Invocation (ROI), Mobile Agents (MA), Common Object Request Broker Architecture (CORBA), Web Services (WS), RPC, and RMI (Dejan, LaForge, & Chauhan, 1998). In this article, we will focus on two particular paradigms: The Web Services and the Mobile Agents. WS defines a standard to invoke distant applications and to recover results across the Web. Its invocation is made in synchronous mode. MA has the faculty to move easily between a network’s hosts to execute user requests. MA communication is made in asynchronous mode. The fusion of these two complementary technologies will solve many problems. This article is composed of the following sections: In the first two sections, we introduce the concepts of WS and MA, their advantages and disadvantages. In the third section, we present different kinds of interaction between MA and WS. Finally, we study an example in the last section.


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