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Biology subjects

Basu, P.

Publications and source records attributed to Basu, P..

4 recordsLinked to original sources

The variations of human miRNAs and Ising like base pairing models

miRNAs are small about 22-base pair long, RNA molecules are of extreme biological importance. Like other longer RNA molecules, messages in miRNAs are encoded by the permutations of only four nucleotide bases represented by A, U, C and G. However, just like words in any language, not all combination of these alphabets make a meaningful word. In fact, we find that the distributions of nucleotides bases in human miRNAs show significant deviation from randomness. First, a miRNA sequence containing four bases are mapped into a binary string with three kinds of classifications according to their chemical properties. Then, we propose a simple nearest neighbor model (Ising model) to understand the statistical variations in human miRNAs.

bioinformatics

Making honey bees lie: experimental dissociation of flight experience and dance communication.

Honey bees use their dance to communicate flight distance and direction of a food source to their nest mates in the hive. How bees transpose flight information to generate a corresponding walking (dance) behavior is still unknown. We now present a detailed study of the changes in dance duration of individual bees after shifting feeder distance. Our experiments indicated that most bees needed two or more foraging trips to the new position before showing an updated dance duration. In addition, only a few bees significantly changed dance duration immediately, whereas most bees first produced intermediary durations. Double shift experiments showed that under certain conditions bees do not update dance duration but continued to perform dance duration for the previously visited feeder position. We propose that generation of dance information involves two memory contents one for newly acquired and one for previously stored distance information.\n\nOne Sentence SummaryGeneration of dance information is temporally separated from immediate flight experience and involves two different memory contents.

animal behavior and cognition

Distribution of Purines and Pyrimidines over miRNAs of Human, Gorilla and Chimpanzee

Meaningful words in English need vowels to break up the sounds that consonants make. The Nature has encoded her messages in RNA molecules using only four alphabets A, U, C and G in which the nine member double-ring bases (adenine (A) and Guanine (G)) are purines, while the six member single-ring bases (cytosine (C) and uracil (U)) are pyrimidines. Four bases A, U, C and G of RNA sequences are divided into three kinds of classifications according to their chemical properties. One of the three classifications, the purine-pyrimidine class is important. In understanding the distribution (organization) of purines and pyrimidines over some of the non-coding regions of RNA, all miRNAs from three species of Family Hominidae (namely human, gorilla and chimpanzee) are considered. The distribution of purines and pyrimidines over miRNA shows deviation from randomness. Based on the quantitative metrics (fractal dimension, Hurst exponent, Hamming distance, distance pattern of purine-pyrimidine, purine-pyrimidine frequency distribution and Shannon entropy) five different clusters have been made. It is identified that there exists only one miRNA in human hsa-miR-6124 which is purely made of purine bases only.\n\nAMS Subject Classification: 92B05 & 92B15

bioinformatics

Sugar intake elicits a small-scale search behavior in flies and honey bees that involves capabilities found in large-scale navigation

Social insects, particularly bees and ants, show exceptional large-scale navigational skills to find and carry back food to their nests. Honey bees further evolved a symbolic communication to direct nest mates to attractive food sources. Till now it is unclear how these capabilities evolved. Sixty years ago, Vincent Dethier demonstrated that a small-scale sugar-elicited search behavior identified in flies shows remarkable similarities with honey bee dance behavior. Those findings suggested that both behaviors are based on common mechanisms and are likely evolutionary related. We now present for the first time a detailed comparison of the sugar-elicited search behavior in Drosophila melanogaster and Apis mellifera. In both species, intake of sugar elicits a complex of searching responses. The most obvious response was an increase in turning frequency, but more importantly we found that flies and honey bees returned to the location of the sugar drop. They even returned to the food location when we prevented them from using visual and chemosensory cues indicating that this small scale local search involves path integration mechanisms. Finally, we show that visual landmarks presented in the vicinity of the sugar drop affected the search trajectory and in honey bees the sugar intake induced learning of landmarks. Together, our experiments indicate that the sugar-elicited local search exhibits two major behavioral capabilities of large-scale navigation, path integration and landmark orientation.\n\nSignificance StatementTo search for food social insects evolved sophisticated strategies of spatial orientation and large-scale navigation. We now show that even a small-scale local search behavior in solitary flies and social honey bees involves path integration and landmark learning two major mechanisms of large-scale navigation. We propose that in the future sugar-elicited local search can be used to identify neural circuits involved in navigation, path integration, and landmark learning.

animal behavior and cognition