Co-detection: Ultra-reliable Nanoparticle-Based Electrical Detection of Biomolecules in the Presence of Large Background Interference

Contrary to popular belief, we report that background interference in conductimetric biochips can be exploited using a novel "co-detection" principle to significantly improve the reliability of detecting trace quantities of biomolecules. The technique called "co-detection" exploits the non-linear redundancy amongst synthetically patterned biomolecular logic circuits for deciphering the presence or absence of target biomolecules in a sample. In this paper, we demonstrate the "co-detection" principle on gold-nanoparticle based conductimetric soft-logic circuits which uses a silver-enhancement technique for signal amplification. Using co-detection, we have been able to measure a 1000 times improvement in the reliability of detecting mouse IgG at concentration levels that are 10^5^ lower than the concentration of rabbit IgG which serves as background interference

Índices de velocidade e potência de testes e itens

A simple index is proposed to measure speed or power components of a test. The index is independent of position of the items and provides necessary and sufficient condition for pure speed test and pure power test and enables testing of statistical hypothesis to infer that the test can be taken as a speed test or a power test. Similar index of an item is also proposed to reflect whether the item is a speed item or a power item. The proposed index C is a ratio such that C = 0 ⟺Pure power test and C = 1⟺Pure speed test facilitating computation of similar index of each item and statistical test of significance. Properties of the index discussed. Operational method outlined to modify a test to speed or power test. Items can be ranked with respect to such item-wise index. Identification of power items and speed items help to modify the test to a speed or power test by deleting items in stages, if speediness (or power) is not intended. Relationship between index for the test and item-wise indices derived.É proposto um índice simples para medir a velocidade ou os componentes de potência de um teste. O índice é independente da posição dos itens e fornece condições necessárias e suficientes para o teste de velocidade pura e teste de potência pura e permite testar a hipótese estatística para inferir que o teste pode ser tomado como um teste de velocidade ou um teste de potência. Um índice semelhante de um item é também proposto para reflectir se o item é um item de velocidade ou um item de potência. O índice C proposto é um rácio tal que C = 0 ⟺Pure test de potência e C = 1⟺Pure test de velocidade facilitando o cálculo de índice semelhante de cada item e teste estatístico de significância. Propriedades do índice discutido. Método operacional delineado para modificar um teste de velocidade ou de potência.  Os itens podem ser classificados em relação a esse índice por item. A identificação de itens de potência e itens de velocidade ajuda a modificar o teste para um teste de velocidade ou de potência, eliminando itens em fases, se a velocidade (ou potência) não estiver prevista. Relação entre o índice para o teste e os índices derivados do item

A Framework for Analyzing Online Cross-correlators using Price's Theorem and Piecewise-Linear Decomposition

Precise estimation of cross-correlation or similarity between two random variables lies at the heart of signal detection, hyperdimensional computing, associative memories, and neural networks. Although a vast literature exists on different methods for estimating cross-correlations, the question what is the best and simplest method to estimate cross-correlations using finite samples ? is still not clear. In this paper, we first argue that the standard empirical approach might not be the optimal method even though the estimator exhibits uniform convergence to the true cross-correlation. Instead, we show that there exists a large class of simple non-linear functions that can be used to construct cross-correlators with a higher signal-to-noise ratio (SNR). To demonstrate this, we first present a general mathematical framework using Price's Theorem that allows us to analyze cross-correlators constructed using a mixture of piece-wise linear functions. Using this framework and high-dimensional embedding, we show that some of the most promising cross-correlators are based on Huber's loss functions, margin-propagation (MP) functions, and the log-sum-exp functions.Comment: 9 figure, 13 page

Characterization of DNA\u27s from several Neurospora species

Characterization of DNA\u27s from several Neurospora specie

Cell Surface Binding and Internalization of Aβ Modulated by Degree of Aggregation

The amyloid peptides, Aβ40 and Aβ42, are generated through endoproteolytic cleavage of the amyloid precursor protein. Here we have developed a model to investigate the interaction of living cells with various forms of aggregated Aβ40/42. After incubation at endosomal pH 6, we observed a variety of Aβ conformations after 3 (Aβ3), 24 (Aβ24), and 90 hours (Aβ90). Both Aβ4224 and Aβ4024 were observed to rapidly bind and internalize into differentiated PC12 cells, leading to accumulation in the lysosome. In contrast, Aβ40/4290 were both found to only weakly associate with cells, but were observed as the most aggregated using dynamic light scattering and thioflavin-T. Internalization of Aβ40/4224 was inhibited with treatment of monodansylcadaverine, an endocytosis inhibitor. These studies indicate that the ability of Aβ40/42 to bind and internalize into living cells increases with degree of aggregation until it reaches a maximum beyond which its ability to interact with cells diminishes drastically