Recent experiments with combinatorial libraries of de novo proteins have demonstrated that sequences designed to contain polar and non-polar amino acid residues arranged in an alternating pattern form fibrillar structures resembling beta-amyloid. This finding prompted us to probe the distribution of alternating patterns in the sequences of natural proteins. Analysis of a database of 250,514 pro...

This paper investigates the impact of puncturing on finite-length polar codes in which a puncturing pattern p = (p0, ..., pN ) is applied to a length-N polar code.. We first introduce two virtual channels to stochastically model the punctured (untransmitted) bits, which are respectively called useless channel model (UCM) and deterministic channel model (DCM). Under each model, we derive boolean...

In this study, we investigate the role of polar secretion and the resulting asymmetry in the cell wall in establishing polarity in Fucus zygotes. We have utilized brefeldin-A to selectively interrupt secretion of Golgi-derived material into the cell wall as assayed by toluidine blue O staining of sulfated fucoidin. We show that the polar secretion of Golgi-derived material is targeted to a cort...

To investigate possible roles of polar auxin transport in vein patterning, cotyledon and leaf vein patterns were compared for plants grown in medium containing polar auxin transport inhibitors (N-1-naphthylphthalamic acid, 9-hydroxyfluorene-9-carboxylic acid, and 2,3,5-triiodobenzoic acid) and in medium containing a less well-characterized inhibitor of auxin-mediated processes, 2-(p-chlorophyno...

Motivated by observed anomalous features in cycle 23, as inferred from records of photospheric magnetic flux, we develop a flux transport dynamo–based scheme in order to investigate the physical cause of such anomalies. In this first study we focus on understanding anomalies occurring in the polar field evolutionary pattern in cycle 23, namely, why the polar reversal in cycle 23 was slow, why a...

How order can emerge spontaneously from a disordered system has always fascinated scientists from numerous disciplines. Especially in active systems like flocks animals, self-propelled microorganisms or the cytoskeleton, a unifying understanding of the pattern formation remains elusive. This is attributed to the inherent complexity of most model systems that prevents a thorough identification o...

In this paper an attempt has been made to compute cross-polarization of millimeter waves in the 30-35 GHz frequency range due to rain. Laws and Parson’s drop size distributions for oblate spheroid drops at 20°C ITU-R (2002) model has been used to predict cross-polarization discrimination (XPD) for circular polarization. The study includes a number of earth stations in India, namely, Ahmedabad, ...

The uni-polar orthogonal codes, with code length 'n' and code weight 'w' having auto-correlation and cross-correlation constraints equal to 1, can be designed with proposed algorithm. This proposed scheme design all the possible groups containing maximum number of orthogonal codes as per Johnson bounds. In this case, each of the designed groups is independent with other groups of uni-polar orth...