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31.
The ability of neonate macaque monkeys to learn to respond to artificial spatial sensory information was studied through the use of compact, head-worn, electronic spatial sonars with audible displays, which translate spatial information into auditory dimensions specifying distance, direction, and surface characteristics. Three animals were born in the dark and raised without vision for 1 to 3 months while wearing either the Binaural Sensory Aid (Animal 1; Kay, 1974) or the Trisensor (Animals 2 and 3; Easton & Jackson, 1983) airborne sonars. Each animal demonstrated alertness to information transmitted by the devices in spontaneous reaching or reinforced discrimination tasks, and more device-related, perceptual-motor activities were observed when the sensors were switched on than when they were switched off. The results show that neonate monkeys can learn effective use of information obtained from sensory substitution devices through unstructured interaction with the environment. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
32.
Comparative analysis of CRISPR loci in lactic acid bacteria genomes   总被引:1,自引:0,他引:1  
Clustered regularly interspaced short palindromic repeats (CRISPR) are hypervariable loci widely distributed in bacteria and archaea, that provide acquired immunity against foreign genetic elements. Here, we investigate the occurrence of CRISPR loci in the genomes of lactic acid bacteria (LAB), including members of the Firmicutes and Actinobacteria phyla. A total of 102 complete and draft genomes across 11 genera were studied and 66 CRISPR loci were identified in 26 species. We provide a comparative analysis of the CRISPR/cas content and diversity across LAB genera and species for 37 sets of CRISPR loci. We analyzed CRISPR repeats, CRISPR spacers, leader sequences, and cas gene content, sequences and architecture. Interestingly, multiple CRISPR families were identified within Bifidobacterium, Lactobacillus and Streptococcus, and similar CRISPR loci were found in distant organisms. Overall, eight distinct CRISPR families were identified consistently across CRISPR repeats, cas gene content and architecture, and sequences of the universal cas1 gene. Since the clustering of the CRISPR families does not correlate with the classical phylogenetic tree, we hypothesize that CRISPR loci have been subjected to horizontal gene transfer and further evolved independently in select lineages, in part due to selective pressure resulting from phage predation. Globally, we provide additional insights into the origin and evolution of CRISPR loci and discuss their contribution to microbial adaptation.  相似文献   
33.
    
Luminescent gold nanoclusters are rapidly gaining attention as efficient theranostic targets for imaging and therapeutics. Indeed, their ease of synthesis, their tunable optical properties and tumor targeting make them potential candidates for sensitive diagnosis and efficacious therapeutic applications. This concept highlights the key components for designing gold nanoclusters as efficient theranostics focusing on application in the field of oncology.  相似文献   
34.
    
In order to study the microscopic nature of the hydrated proton and its transport mechanism, we have introduced a multistate empirical valence bond model, fitted to ab initio results. This model was applied to the study, at low computational cost, of the structure and dynamics of an excess proton in liquid water. The quantum character of the proton is included by means of an effective parametrization of the model using preliminary path-integral calculations. The mechanism of proton transfer is interpreted as the translocation of a special O–H+–O bond along the hydrogen network, i.e., a series of reactions of the form H5O2+ + H2O ⇌ H2O + H5O2+, rather than H3O+ + H2O → H2O + H3O+ as usually described. The translocation of the special bond can be described as a diffusion process with a jump time of 1 ps. A time-dependent correlation function analysis of the special pair relaxation yields two timescales, 0.3 and 3.5 ps. The first time is attributed to the interconversion between a delocalized (H5O2+-like) and a localized (H9O4+-like) form of the hydrated proton within a given special pair. The second one is the relaxation time of the special pair, including return trajectories. The computed diffusion constant, as well as the isotopic substitution effect, are in good agreement with experiment. The hydration structure around the excess proton is discussed in terms of various radial distribution functions around the water molecules involved in the special pair and those in the first solvation shell. The hydrogen-bond-dynamics which accompanies the translocation process is studied statistically. The “Moses mechanism” proposed by Noam Agmon for proton mobility in water is partially verified by our simulations.  相似文献   
35.
    
ABSTRACT

The present article is devoted to quantifying the contribution of pores and cracks in the decrease of the effective thermal conductivity of thermal barrier coatings (TBCs). A finite-difference-based model is used for the computation of heat transfer through a porous structure. Each pixel of a binary picture describing the pore network is interpreted as a cell of integration of the heat conduction equation. A thermal gradient is applied and a large system of linear Equations is subsequently derived. Since it has a strong influence on the required CPU time, particular attention is given to the solving procedure.  相似文献   
36.
Wireless Networks - With the constant increase of throughput demands, maximizing the wireless network capacity has always been a crucial issue. Network densification becomes one of the adopted...  相似文献   
37.
This paper presents an empirical micro-simulation model of the teaching and the testing process in the classroom (Programs and sample data are available – the actual names of pupils have been hidden). It is a non-econometric micro-simulation model describing informational behaviors of the pupils, based on the observation of the pupils’ communication behavior during lessons and tests. The representation of the knowledge process is very simplified. However, we tried to study the involvements of individual motivation, capability and relationship with other pupils of each pupil, to compare them to the new-classical (and keynesian) and Austrian information and knowledge theoretical results. It is a first step and future development should concern expectation behaviors and dynamics. This paper aims too to give, we hope so, some criteria of pupils’ rationality in the classroom.  相似文献   
38.
We present methods used to determine the linear or nonlinear static response and the linear dynamic response of an adaptive optics (AO) system. This AO system consists of a nonlinear microelectromechanical systems deformable mirror (DM), a linear tip-tilt mirror (TTM), a control computer, and a Shack-Hartmann wavefront sensor. The system is modeled using a single-input-single-output structure to determine the one-dimensional transfer function of the dynamic response of the chain of system hardware. An AO system has been shown to be able to characterize its own response without additional instrumentation. Experimentally determined models are given for a TTM and a DM.  相似文献   
39.
This paper describes 4 cases of spontaneous exposure and sequestration of alveolar bone. While one case was associated with an allergic mucositis, the other three were idiopathic involving large lingual exostoses.  相似文献   
40.
The metabolic pathways contributing to phosphatidylcholine biosyntheses in Plasmodium falciparum, the malaria-causing parasite, was explored by electrospray ionization mass spectrometry. Phosphatidylcholine produced by the CDP-choline pathway and by the methylation of phosphatidylethanolamine was identified and quantified through isotopic labeling experiments. A straightforward method based on cone voltage directed in-source fragmentations and relative abundance measurement of endogenous versus deuterated specific fragment ions was developed for simple and rapid automated data acquisition. Such high-throughput analytical protocol allowed us to measure the relative contribution of two different metabolic pathways leading to phosphatidylcholine without performing technically more demanding and time-consuming MS/MS or LC/MS experiments.  相似文献   
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