957 resultados para Transition to Active Life


Relevância:

100.00% 100.00%

Publicador:

Resumo:

Community languages have a place in early years education for children in prior-to-school settings and students in formal schooling. Australian curricula treat the languages of the local community as both content and resource for learning. In this article we look at the potential of dual language and multiple language storybooks for teaching about linguistic diversity and developing literacy skills, highlighting the potential of paired and shared reading.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The crystal structure of beta-hydroxyacyl acyl carrier protein dehydratase of Plasmodium falciparum (PfFabZ) has been determined at a resolution of 2.4 angstrom. PfFabZ has been found to exist as a homodimer (d-PfFabZ) in the crystals of the present study in contrast to the reported hexameric form (h-PfFabZ) which is a trimer of dimers crystallized in a different condition. The catalytic sites of this enzyme are located in deep narrow tunnel-shaped pockets formed at the dimer interface. A histidine residue from one subunit of the dimer and a glutamate residue from the other subunit lining the tunnel form the catalytic dyad in the reported crystal structures. While the position of glutamate remains unaltered in the crystal structure of d-PffabZ compared to that in b-PfFabZ, the histidine residue takes up an entirely different conformation and moves away from the tunnel leading to a His-Phe cis-trans peptide flip at the histidine residue. In addition, a loop in the vicinity has been observed to undergo a similar flip at a Tyr-Pro peptide bond. These alterations not only prevent the formation of a hexamer but also distort the active site geometry resulting in a dimeric form of FabZ that is incapable of substrate binding. The dimeric state and an altered catalytic site architecture make d-PfFabZ distinctly different from the FabZ structures described so far. Dynamic light scattering and size exclusion chromatographic studies clearly indicate a pH-related switching of the dimers to active hexamers. (c) 2006 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserv.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

An experimental study has been made of transition to turbulence in the free convective flows on a heated plate. Observations have been made with the plate vertical and inclined at angles up to about 50° to the vertical, both above and below the plate. A fibre anemometer was used to survey the region of intermittent turbulence. Information has thus been obtained about the range of Grashof numbers over which transition takes place. Even when the plate is vertical the region of intermittent turbulence is long. When it is inclined, this region becomes still longer in the flow below the plate as a result of the stabilizing stratification, a Richardson number effect. It is possible to have a whole flow such that it should be described as transitional, not laminar or turbulent. It was noticed that in this flow and the vertical plate one, the velocity during the laminar periods could be either of two characteristic values, one of them close to zero. The behaviour above an inclined plate could be interpreted largely as a trend towards the behaviour described in a preceding paper.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The tug of war between a pathogen and its host has been one of the most amazing stories in the field of microbial pathogenesis for ages. The strongest known species of all living organisms is the Homo sapiens and yet it is incredible how a pathogen of the size of few microns is smart enough to defeat this mightiest group of survivors. It is of utmost interest to understand the mechanisms behind the successful habitation of a pathogen inside the ever-resisting and complicate human body. Numerous examples of diseases caused by such pathogens exist which intrigues us to venture in the world of host-pathogen interactions.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The transition process from steady convection to chaos is experimentally studied in thermocapillary convections of floating half zone. The onset of temperature oscillations in the liquid bridge of floating half zone and further transitions of the temporal convective behaviour are detected by measuring the temperature in the liquid bridge. The fast Fourier transform reveals the frequency and amplitude characteristics of the flow transition. The experimental results indicate the existence of a sequence of period-doubling bifurcations that culminate in chaos. The measured Feigenbaum numbers are delta(2) = 4.69 and delta(4) = 4.6, which are comparable with the theoretical asymptotic value delta = 4.669.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

This laboratory guide presents taxonomic information on eggs and larvae of fishes of the Northeast Pacific Ocean (north of California) and the eastern Bering Sea. Included are early-life-history series, illustrations, and comparative descriptions of 232 species expected to spawn here, out of a total 627 species known to occur in marine waters of this area. Meristic and general life-history data are included, as well as diagnostic characters to help identify eggs and larvae. Most of this information has been gleaned from literature, with the addition of 200 previously unpublished illustrations. (PDF file contains 654 pages.)

Relevância:

100.00% 100.00%

Publicador:

Resumo:

In species of Cladocera not forming ephippia, the latent eggs have a sheath formed by glands of the reproductive canals. Representatives of the families Daphniidae and Moinidae Goulden, 1968, in connection with the formation of their complex-structured ephippia, lost these glands. It was investigated whether there are such glands in species the latent eggs of which are enclosed in primitive ephippia. For this, with the help of histological methods, 55 females of Acroperus elongatus (Sars) (Chydoridea) and 88 females of Lathonura rectirostris (O. F. Muller), (Macrothricidae) were collected near Leningrad, were studied.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Through consultations with key fisheries-based stakeholders in four States of India, this study attempts to assess perceptions of fishing communities about the impact of climate change on their lives and livelihoods. It also evaluates the traditional knowledge, institutions and practices of fishing communities that are relevant to climate-change preparedness. The study identifies adaptation and mitigation measures that may need to be adopted by fishing communities and the State in relation to climate change. Based on this overall analysis, the study proposes measures to protect the lives and livelihoods of small-scale fishing communities in the context of climate-change policies and programmes at different levels. This study will be useful for researchers, policymakers, students and anyone interested in climate change and its potential effects on the lives and livelihoods of small-scale fishing communities.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

In this paper we examine triggering in a simple linearly-stable thermoacoustic system using techniques from flow instability and optimal control. Firstly, for a noiseless system, we find the initial states that have highest energy growth over given times and from given energies. Secondly, by varying the initial energy, we find the lowest energy that just triggers to a stable periodic solution. We show that the corresponding initial state grows first towards an unstable periodic solution and, from there, to the stable periodic solution. This exploits linear transient growth, which arises due to nonnormality in the governing equations and is directly analogous to bypass transition to turbulence. Thirdly, we introduce noise that has similar spectral characteristics to this initial state. We show that, when triggering from low noise levels, the system grows to high amplitude self-sustained oscillations by first growing towards the unstable periodic solution of the noiseless system. This helps to explain the experimental observation that linearly-stable systems can trigger to self-sustained oscillations even with low background noise. © 2010 by University of Cambridge. Published by the American Institute of Aeronautics and Astronautics, Inc.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

We observed the decrease of the hysteresis effect and the transition from the stable to the dynamic domain regime in doped superlattices with increasing temperature. The current-voltage characteristics and the behaviours of the domain boundary are dominated by the temperature-dependent lineshape of the electric field dependence of the drift velocity (V(F)), As the peak-valley ratio in the V(F) curve decreases with increasing temperature, the hysteresis will diminish and temporal current self-oscillations will occur. The simulated calculation, which takes the difference in V(F) curves into consideration, gives a good agreement with the experimental results.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

We investigate the transition from static to dynamic electric field domains (EFDs) in a doped GaAs/AlAs superlattice (SL). We show that a transverse magnetic field and/or the temperature can induce current self-oscillations. This observation can be attributed to the negative differential resistance (NDR) effect. Transverse magnetic field and the temperature can increase the NDR of a doped SL. A large NDR can lead to an unstable EFD in a certain range of d.c. bias. (C) 1999 Elsevier Science Ltd. All rights reserved.