Current Issue : April - June Volume : 2011 Issue Number : 2 Articles : 8 Articles
Auditory information is widely used throughout the animal kingdom in both terrestrial and aquatic environments. Some marine species are dependent on reefs for adult survival and reproduction, and are known to use reef noise to guide orientation towards suitable habitat. Many others that forage in food-rich inshore waters would, however, benefit from avoiding the high density of predators resident on reefs, but nothing is known about whether acoustic cues are used in this context. By analysing a sample of nearly 700,000 crustaceans, caught during experimental playbacks in light traps in the Great Barrier Reef lagoon, we demonstrate an auditory capability in a broad suite of previously neglected taxa, and provide the first evidence in any marine organisms that reef noise can act as a deterrent. In contrast to the larvae of species that require reef habitat for future success, which showed an attraction to broadcasted reef noise, taxa with a pelagic or nocturnally emergent lifestyle actively avoided it. Our results suggest that a far greater range of invertebrate taxa than previously thought can respond to acoustic cues, emphasising yet further the potential negative impact of globally increasing levels of underwater anthropogenic noise....
The paper emphasized on the essence of the current ecology research across a wide range of discipline reflecting recent advances in light of growing evidence regarding global environment change and destruction. Ecology abstract focuses on how organizes of all kinds microbes plants and animals interact with their environment and with other organism. Included are relevant papers on revolutionary biology economics and systems as they relate to ecosystem or environment. Comprehensive yet carefully focused coverage makes this on essential resource for scientists concerned with preserving the environment....
Visualization tools for biological data are often limited in their ability to interactively integrate data at multiple scales. These computational tools are also typically limited by two-dimensional displays and programmatic implementations that require separate configurations for each of the user's computing devices and recompilation for functional expansion. Towards overcoming these limitations we have developed Ã?¢ââ??¬Ã?â??ePlantÃ?¢ââ??¬? ( http://bar.utoronto.ca/eplant ) Ã?¢ââ??‰â?¬Å? a suite of open-source world wide web-based tools for the visualization of large-scale data sets from the model organism Arabidopsis thaliana . These tools display data spanning multiple biological scales on interactive three-dimensional models. Currently, ePlant consists of the following modules: a sequence conservation explorer that includes homology relationships and single nucleotide polymorphism data, a protein structure model explorer, a molecular interaction network explorer, a gene product subcellular localization explorer, and a gene expression pattern explorer. The ePlant's protein structure explorer module represents experimentally determined and theoretical structures covering >70% of the Arabidopsis proteome. The ePlant framework is accessed entirely through a web browser, and is therefore platform-independent. It can be applied to any model organism. To facilitate the development of three-dimensional displays of biological data on the world wide web we have established the Ã?¢ââ??¬Ã?â??3D Data Display InitiativeÃ?¢ââ??¬? ( http://3ddi.org )....
The nitrogen cycle is the continuous series of natural processes by which nitrogen passes from the air to the soil, to plants, and ultimately to sustain all animal life, and then return back to the air or soil through decay or denitrification (the loss of nitrogen). Nitrogen is basic element of all living cells. Through nitrogen fixation, nitrogen gas is converted into inorganic nitrogen compound to be used by plants, animals, and people. This conversion is accomplished through the nitrogen cycle in which nitrogen as a gas is carried to the earth’s surface in precipitation. Nitrogen is then used by plant and incorporated in their tissues as plant protein. The nitrogen then passes through the food chain to animals and people. Human intrusion in the nitrogen cycle can result in more or less nitrogen being cycle as part of the nature system. For example, the cultivation of croplands, harvesting of crops, and cutting of forests has caused a decline of the natural occurring nitrogen in the soil. Soil nitrogen can be replenished with manufactured nitrogen fertilizer, animal manure and legumes. Nitrogen from over-fertilization of plant life, industrial discharges, and human and animal waster discharges can add too much nitrogen to the natural system and may have an impact on soil, water, and air quality....
Adaptation in spatially extended populations entails the propagation of evolutionary novelties across habitat ranges. Driven by natural selection, beneficial mutations sweep through the population in a ââ?¬Å?wave of advanceââ?¬Â. The standard model for these traveling waves, due to R. Fisher and A. Kolmogorov, plays an important role in many scientific areas besides evolution, such as ecology, epidemiology, chemical kinetics, and recently even in particle physics. Here, we extend the Fisherââ?¬â??Kolmogorov model to account for mutations that confer an increase in the density of the population, for instance as a result of an improved metabolic efficiency. We show that these mutations invade by the action of random genetic drift, even if the mutations are slightly deleterious. The ensuing class of noise-driven waves are characterized by a wave speed that decreases with increasing population sizes, contrary to conventional Fisherââ?¬â??Kolmogorov waves. When a trade-off exists between density and growth rate, an evolutionary optimal population density can be predicted. Our simulations and analytical results show that genetic drift in conjunction with spatial structure promotes the economical use of limited resources. The simplicity of our model, which lacks any complex interactions between individuals, suggests that noise-induced pattern formation may arise in many complex biological systems including evolution. Mutations that increase an organism's fitness are the fuel for biological evolution. When such beneficial mutations enter a spatially extended population, they spread through the population in a ââ?¬Å?wave of advanceââ?¬Â, first described by R. Fisher and A. Kolmogorov. The force driving these traveling waves is Darwinian selection, which favors individuals with higher fitness. Here, we describe a new type of traveling mutant wave that is driven by non-selective forces instead-- namely by random genetic drift, which refers to the randomness in the reproduction process. These noise-driven waves promote the economical use of a limited resource because they occur whenever a mutation increases the growth yield, which refers to the biomass produced per unit of resource. Since a change in growth yield and growth rate often occur together and with opposite signs, we argue that both types of mechanisms will jointly decide over the fate of a novel mutation. We predict that the population evolves towards an evolutionary optimal carrying capacity, at which selective and non-selective forces just balance....
Recently proposed distributed adaptive estimation algorithms for wireless sensor networks (WSNs) do not consider errors due to noisy links, which occur during the transmission of local estimates between sensors. In this paper, we study the effect of noisy links on the performance of distributed incremental least-mean-square (DILMS) algorithm for the case of Gaussian regressors. More specifically, we derive theoretical relations which explain how steady-state performance of DILMS algorithm (in terms of mean-square deviation (MSD), excess mean-square error (EMSE), and mean-square error (MSE)) is affected by noisy links. In our analysis, we use a spatial-temporal energy conservation argument to evaluate the steady-state performance of the individual nodes across the entire network. Our simulation results show that there is a good match between simulations and derived theoretical expressions. However, the important result is that unlike the ideal links case, the steady-state MSD, EMSE and MSE are not monotonically increasing functions of step size parameter when links are noisy. In addition, the optimal step size is found in a closed form for a special case which minimizes the steady-state values of MSD, EMSE, and MSE in each node....
The aim of the present study is to introduce a probabilistic approach to determine the components of the risk evaluation for rainfall-induced earthflows in medium scale. The Catakli catchment area (Cayeli, Rize, Turkey) was selected as the application site of this study. The investigations were performed in four different stages: (i) evaluation of the conditioning factors, (ii) calculation of the probability of spatial occurrence, (iii) calculation of the probability of the temporal occurrence, and (iv) evaluation of the consequent risk. For the purpose, some basic concepts such as ââ?¬Å?Risk Cubeââ?¬Â, ââ?¬Å?Risk Planeââ?¬Â, and ââ?¬Å?Risk Vectorââ?¬Â were defined. Additionally, in order to assign the vulnerability to the terrain units being studied in medium scale, a new more robust and more objective equation was proposed. As a result, considering the concrete type of roads in the catchment area, the economic risks were estimated as \n3 . 6 Ã?â?? 1 0\n6\nââ??¬\nââ?¬â?in case the failures occur on the terrain units including element at risk, and \n1 2 . 3 Ã?â?? 1 0\n6\nââ??¬\nââ?¬â?in case the risks arise from surrounding terrain units. The risk assessments performed in medium scale considering the technique proposed in the present study will supply substantial economic contributions to the mitigation planning studies in the region....
Morphological information are prerequisite for the bio-systematic studies and breeding. Nature of flower, fertility and seasons are the most important factors for a breeding program. In mulberry, floral characters and seed setting of colchitetraploids and their putative diploid genotypes were studied in March and September months. Male, female and monoecious colchitetraploids exhibited larger inflorescences as compare to their diploid genotypes. Good seed set percentage was found in diploid genotypes as compare to colchitetraploids. Comparatively smaller inflorescences were found in March month than in September month. But, seed set percentage was good in March month compare to September month. For better results in the triploidy breeding, it is suggested that March is the better season in these genotypes....
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