Analysis of the subthreshold current of pocket or halo-implanted nMOSFETs

In this work, we analyzed the subthreshold current (I/sub D/) of pocket implanted MOSFETs using extensive device simulations and experimental data. We present an analytical model for the subthreshold current applicable for any type of FET and show that the subthreshold current of nMOSFETs, which is mainly due to diffusion, is determined by the internal two-dimensional hole distribution across the device. This hole distribution is affected by the electric potential of the gate and the doping concentration in the channel. The results obtained allow accurate modelling of the subthreshold current of future generation MOS devices

Introduction to Protein Structure Prediction

This chapter gives a graceful introduction to problem of protein three- dimensional structure prediction, and focuses on how to make structural sense out of a single input sequence with unknown structure, the 'query' or 'target' sequence. We give an overview of the different classes of modelling techniques, notably template-based and template free. We also discuss the way in which structural predictions are validated within the global com- munity, and elaborate on the extent to which predicted structures may be trusted and used in practice. Finally we discuss whether the concept of a sin- gle fold pertaining to a protein structure is sustainable given recent insights. In short, we conclude that the general protein three-dimensional structure prediction problem remains unsolved, especially if we desire quantitative predictions. However, if a homologous structural template is available in the PDB model or reasonable to high accuracy may be generated

Friction coefficient of a disk in a sheet of viscous fluid: numerical calculation

We study the class C of (generalized) orthogonal polynomial sequences {Pn(x)}n=0∞ satisfying a recurrence relation of the type Pn(x) = (x − cn)Pn−1(x) − λnPn−2(x), n> 1, where λn ≠ 0 and the sequence {λn+1/(cncn+1)}n=1∞ constitutes a chain sequence. We obtain a new characterization of C in terms of the moment sequence associated with an orthogonal polynomial sequence, and contribute to the solution of the problem of determining a (signed) orthogonalizing measure for a member of C

Ritual Cloth As Emblem Of Socio-Religious Values In Indonesia

Recent anthropological studies of Indonesian textiles have reported in detail on the important ritual role of locally-made heirloom cloths among a range of ethnic groups throughout the archipelago. Moreover, the few extant studies with a local comparative bias have shown how the function of one particular textile may vary between people living in different villages or belonging to different social groups. Geirnaert has pointed out that, obviously, this indicates that textiles may form part of a wider geographical or symbolical system (Geirnaert 1992:xxviii). It has also been shown that this type of comparative effort can be taken beyond the archipelago (see Gittinger 1992; Maxwell 1990). As yet, a concerted attempt at comparison of the meanings of ritual cloth among different ethnic groups within Indonesia has not been undertaken. Therefore, our panel will compare the manner in which one type of highly valued, locally-made ceremonial cloth functions among three ethnic groups in Indonesia: the Lio of central Flores, the Minangkabau of west Sumatra and villagers from Kerek, near Tuban on the northeast coast of Java. The comparison concerns the most highly-valued type of textile and its ritual role among the highest-ranking social group in each of the three cultures: the lawo butu, the beaded sarong of the Lio, the kain sandang gobo, a heavily gold-decorated shoulder cloth of the Minangkabau and the kain kembangan, the flowered cloth of the villagers of Kerek. Certain differences in the symbolic meaning and function of the three cloth types will appear to be linked to the different forms of social organization and religious adherence of each of the three groups. Changes over time have influenced the cloths\u27 function. Weiner\u27s distinction between alienable property -which may be owned by individuals or sections of the community, and is marketable or exchangeable - and inalienable property -which is collectively and eternally owned by the whole group -in Oceania (Weiner 1992), has served as an additional analytical tool for the case of the Indonesian textiles

The Application of Bacteriophage for the Elimination of Pathogenic Bacteria in Compost

The demand for organically grown produce is rapidly rising in the United States, resulting in a resurgence of natural fertilizers, such as animal waste, being used in agriculture. Currently, there are guidelines set by the USDA for the proper processing of fecal materials through composting; however food-borne illnesses associated with fresh-produce have become more and more common. Research is being conducted toward developing more effective treatments of fecal waste to reduce the survival of harmful bacteria. One possible form of treatment is through the use of bacteriophages that are able to \u27seek and destroy\u27 specific bacteria. The objectives of this study were to: 1) isolate and characterize strains of bacteriophage capable of lysing Salmonella spp. and Escherichia coli O157:H7, 2) to develop and optimize a cocktail of these bacteriophages, and 3) to reduce pathogens in compost by administering bacteriophage to autoclaved and non-autoclaved composts inoculated with either Salmonella or E. coli O157:H7. In the characterization and isolation of bacteriophage study, thirty-four Salmonella-specific and forty-two E. coli O157:H7-specific bacteriophages were isolated from raw sewage using an enrichment method. Ten phage strains for each pathogen were selected for use in optimization studies in liquid media. Phages exhibited little to no effectiveness in 0.85% saline or SM buffer, but were highly active in tryptic soy broth (TSB). Electron microscopy and restriction digest analysis were used to characterize the selected phages. A five-phage cocktail was developed and tested against five strains of Salmonella enterica encompassing four serovars: Typhimurium, Poona, Newport and Enteritidis. The cocktail was effective at preventing the growth of Salmonella Typhimurium 8243 indefinitely in TSB. Treatments of phage cocktail suppressed the growth of other strains initially, but had little effect on preventing the development of phage resistance. For the compost study, both autoclaved and non-autoclaved dairy compost was inoculated with 105 CFU/g of either Salmonella Typhimurium or E. coli O157:H7 and held for 24 h followed by phage treatment. Reductions of 2.34, 2.41 and 2.56 logs were observed in non-autoclaved compost inoculated with Salmonella Typhimurium 8243 at phage multiplicity of infections (MOIs) of 1, 10 and 50, respectively. An identical study using E. coli O157:H7 strain 0923-21 had reductions of 0.17, 1.21 and 1.5 logs with MOIs of 1, 10 and 50, respectively. The impact of water activity in compost on pathogen reductions by phages was further studied. Compost prepared at water activity levels of 0.9, 0.95 and 0.98 yielded no reductions as a result of phage treatment in any of the trials. Non-autoclaved compost inoculated with Salmonella had reductions of 2 to 3 logs when the water activity was close to 1. Non-autoclaved compost inoculated with E. coli O157:H7 had a one log decrease after phage treatment. Only slight reductions in E. coli O157:H7 and Salmonella were detected in the autoclaved compost (aw=0.999) as a result of 2 to 3 logs of bacterial growth prior to phage treatment. The results indicate that specific bacteriophage cocktails are effective at reducing pathogen populations in compost under certain conditions, such as an appropriate ratio of phage to bacteria and high water activity. This suggests that phage treatment may be useful as a supplement to composting for the further elimination of pathogenic bacteria in animal waste

Three-dimensional Ising model in the fixed-magnetization ensemble: a Monte Carlo study

We study the three-dimensional Ising model at the critical point in the fixed-magnetization ensemble, by means of the recently developed geometric cluster Monte Carlo algorithm. We define a magnetic-field-like quantity in terms of microscopic spin-up and spin-down probabilities in a given configuration of neighbors. In the thermodynamic limit, the relation between this field and the magnetization reduces to the canonical relation M(h). However, for finite systems, the relation is different. We establish a close connection between this relation and the probability distribution of the magnetization of a finite-size system in the canonical ensemble.Comment: 8 pages, 2 Postscript figures, uses RevTe

Tracking repeats using significance and transitivty.

transitivity; extreme value distribution Motivation: Internal repeats in coding sequences correspond to structural and functional units of proteins. Moreover, duplication of fragments of coding sequences is known to be a mechanism to facilitate evolution. Identification of repeats is crucial to shed light on the function and structure of proteins, and explain their evolutionary past. The task is difficult because during the course of evolution many repeats diverged beyond recognition. Results: We introduce a new method TRUST, for ab-initio determination of internal repeats in proteins. It provides an improvement in prediction quality as compared to alternative state-of-the-art methods. The increased sensitivity and accuracy of the method is achieved by exploiting the concept of transitivity of alignments. Starting from significant local suboptimal alignments, the application of transitivity allows us to: 1) identify distant repeat homologues for which no alignments were found; 2) gain confidence about consistently well-aligned regions; and 3) recognize and reduce the contribution of nonhomologous repeats. This reassessment step enables us to derive a virtually noise-free profile representing a generalized repeat with high fidelity. We also obtained superior specificity by employing rigid statistical testing for self-sequence and profile-sequence alignments. Assessment was done using a database of repeat annotations based on structural superpositioning. The results show that TRUST is a useful and reliable tool for mining tandem and non-tandem repeats in protein sequence databases, able to predict multiple repeat types with varying intervening segments within a single sequence