Cluster Designs

The first step in that process occurs when a person is exposed to HIV (usually through sexual contact or transfer of blood from an infected to a healthy person). HIV travels through the bloodstream until it comes into contact with certain types of white blood cells that contain proteins known as CD4 (cluster designation 4) receptor sites on their surface. The virus then attaches itself to the CD4 receptor and injects a protein (called the p24 protein) into the host cell s interior. The p24 protein carries the genetic information that controls reproduction of HIV. 

Biomimics of noncatalytic, or structural, zinc generally focus on zinc-thiolate clusters designed after the metal—thiolate clusters of metal-lothionein (see Section IV,C). Adamantoid anions of formula [ (jiz-SPh)6(ZnSPh)4] are targets of synthetic and structural study, where each metal ion is coordinated in tetrahedral fashion by bridging and terminal thiolate ligands (see Hencher et al., 1985 Dean and Vittal, 1987, and references cited therein). 

Ariga K, Utakawa T, Michiue A, Kikuchi J-I. Spider-net amphiphiles as artificial lipid clusters design, synthesis, and accommodation of lipid components at the air-water interface. Langmuir 2004 20 6762-6769. 

A soluble NADH dehydrogenase consisting of a 51-kDa peptide that binds both the FMN and also one tetranuclear Fe - S cluster (designated N3) and a 24-kDa peptide that carries a binuclear Fe-S center designated Nib. (2) A 75-kDa peptide bearing two binuclear Fe-S centers, one of which is called Nla and also 47-, 30-, and 13-kDa peptides. One of these carries tetranuclear center N4. (3) A group of insoluble, relatively nonpolar proteins, one of which carries tetranuclear cluster N2. 

Abbreviations-. CD, cluster designation (surface markers) ConA, concanavalin A (aT cell mitogen) IFNy, interferon-gamma IL, interleukin PBMC, peripheral blood mononuclear cells TNFa, tumour necrosis factor-alpha. 

The CDC sampling plan follows a complex, stratified, multistage, probability cluster design to select a representative sample of the civilian noninstitutionalized population of the United States. Relevant details are... 

We call this approach cluster design, where we first divide each set of BBs into subsets (clusters) of similar compounds, then making BBLs by separate SMDs for each cluster. The approach has positive consequences Simple designs result, because structural variation in each subset is limited. Relevant descriptors are not too hard to find because subsets can often be seen as backbone + substituents, and we have lots of good substituent descriptors for e.g. size, lipophilicity, polarity and polarizability. Finally, QSARs of each cluster are possible to construct for the same reasons, making results interpretable and predictions possible. 

K. Ariga, T. Urakawa, A. Michiue, J. Kikuchi, Spider-Web Amphiphile as Artificial Lipid Clusters Design, Synthesis, and Accommodation of Lipid Components at the Air-Water Interface , Langmuir, 20, 6762 (2004)... 

Flerder, P.M., Stikkelman R.M. (2004), Methanol-based Industrial cluster design a study of the design options and design process, in Ind. Eng. Chem. Res, 43, p3879-3885... 

Note Studies marked PC (placebo control) included a control group, and others did not. CD, cluster designation IL, interleukin IFN, interferon M, men NC, no change NK, natural killer P, proliferation W, women. 

Fig. 4. Disruption of the synapsin-dependent vesicle pool by presynaptic microinjection of synapsin antibodies in the lamprey reticulospinal synapse. (A) Electron micrograph of a control synapse. (B) A synapse in an axon injected with synapsin antibodies. The axon was lightly stimulated (1 Hz for 12 min) and allowed to rest for 90 min before fixation. Note that a narrow rim of vesicles remains in the antihody-injected synapse. (O Immunogold staining of a reticulospinal synapse with synapsin antibodies. Note that the vesicles adjacent to the presynaptic membrane are almost devoid of gold particles. (D) Visualization of the filamentous cytomatrix that overlaps with the synaptic vesicle pool that remains after perturbation of synapsins. The electron micrograph shows a synapse in a normal axon (i.e. no microinjection or stimulation had been performed) stained with phosphotungstic acid (Gustafsson et al., 1996). The filamentous eytomatrix (arrowheads) at the presynaptic membrane is visible, but not the synaptic vesicle cluster. Designations as in Fig. 1. Scale bar, 0.2 p.m. Reprinted from Brodin et al. (1995) Eur J Neurosci 9 2503-2511, with permission.

ACTG AIDS Clinical Trail Group AIDS acquired immune deficiency syndrome bDNA branched DNA CD cluster designation... 

The LINUX cluster had been managed under continually increasing load for a period of months. Systems administrators had responded by incremental addition of PCs, but the performance had shown continued decline. The system was loaded near capacity, which is often far below theoretical, 70% of maximum being a common benchmark. Another feature of the system, which is especially relevant to clusters, was the impact of component failure. For computers, this is likely the disk drive. Drives have a mean time between failure of one to two years and follow a bathtub curve of burn-in failure, followed by reliable performance and then high failure near the end of the lifecycle. Cluster design must take into account the need for graceful degradation. 

Evidence has been presented for the presence of four Fe4S4-like clusters (designated as P-clusters) in [FeMo], The P-cIusters are, however, by no means ordinary Fc4S4 clusters, and may not be Fe4S4 clusters at all. P-clusters are manifestin electronic absorption and, especially, MCD and Mossbauer spectra of [FeMo]. These spectra are clearly not conventional i.e., they are not... 

In the general case, cluster design is applied to a number of candidate molecules, as in D-optimal design, but on a different criterion of representativeness. However, the same clustering approach can also be used for selecting the representative items of a multivariate characterization of discrete systems. 

The simplest model, of course, is a free cluster. This is merely a finite, mostly rather small part of the crystal, used without any modification. In most cases, such a cluster consists of an array of mxnxp atoms or imit cells, where m, n, and p denote the niunber of atoms or imit cells in the three Cartesian directions or along the crystallographic axes. Other cluster designs are also used occasionally. Figure 1 shows two examples The first one in Fig. la is a small NiO cluster containing two layers of nine atoms each, i.e., a 3x3x2 cluster in the above notation. Clusters of this kind have been used frequently to represent the (100) surface plane of crystals with rock salt structure (see below). The second example in Fig. lb is a cluster which is part of the wurtzite structure... 

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