Community structure has been widely identified as a feature of many real-world networks. It has been shown that the antigenic diversity of a pathogen population can be significantly affected by the contact network of its hosts; however, the effects of community structure have not yet been explored. Here, we examine the congruence between patterns of antigenic diversity in pathogen populations i...

Bacterial abundance, biomass, cell volume, and morphological diversity were studied in sediment samples collected from the coastal area of the eastern mid Adriatic Sea. Samples from the topmost 10 cm of sediment were taken monthly from January to December 2002. The number of bacteria varied from 3.54 x 109 cells g–1 in July to 8.08 x 109 cells g–1 in September. Biomass was lowest in May (78 μg ...

Evolutionary genetics studies the patterns and mechanisms of genetic changes underlying evolutionary change. Because biological diversity at all levels (including population, species, and ecosystem diversity) has a genetic basis and is a result of evolution, evolutionary genetics provides insight into the ultimate mechanisms creating biodiversity. Evolutionary genetics utilizes empirical tools ...

This paper proposes a class of full space diversity full rate space-time turbo codes. Both parallel concatenated and serially concatenated codes are designed. The full space diversity design is facilitated by a rank theory. Compared with space-time trellis codes, the simulations show the space-time turbo codes have excellent performance in both quasi-static fading channels and time varying fadi...

We present a novel full-rate full-diversity orthogonal space-time block code for QPSK modulation and 4 transmit antennas based on quaternionic algebra. The code does not result in constellation expansion unlike other full-rate full-diversity codes in the literature. The quaternionic structure of the code is exploited to reduce the complexity of maximum likelihood (ML) coherent decoding from a s...

The recently developed IEEE 802.16e specifications for broadband wireless access include three multiple-input multiple-output (MIMO) profiles employing 2×2 spacetime codes (STCs) and two of those are mandatory on the downlink of Mobile WiMAX systems. One of these is full rate, and the other is full diversity, but neither of them has both of the desired features. The third profile, which is not ...

Space-time (ST) coding techniques exploit the spatial diversity afforded by multiple transmit and receive antennas to achieve reliable transmission in scattering-rich environments. ST block codes are capable of realizing full diversity and spatial coding gains at relatively low rates; ST trellis codes can achieve better rate-diversity tradeoffs at the cost of high complexity. On the other hand,...