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SUMMARY: Cyanobacteria are ancient organisms that contribute significantly to primary production in aquatic ecosystems. Although they are a group of microbes present in a wide range of environments, their diversity on anthropogenic substrates, namely microplastics, is still largely unknown. In the present study, we describe a new genus and species of cyanobacteria from the Nodosilineaceae family. Strains were isolated from foam microplastic particles obtained from beach sediments facing the Singapore Strait. This species is morphologically similar to the polyphyletic, cosmopolitan Leptolyngbya spp.; however, it forms an independent clade with 16S rRNA phylogeny and has a unique 16S–23S internal transcribed spacer secondary structure. To date, no cyanobacteria have been isolated and cultured from the surfaces of microplastic particles. Using a polyphasic approach combining morphological, phylogenetic and ecological traits, we describe a new genus and species Sphaerothrix gracilis. The presence of certain cyanobacteria rafting on microplastic surfaces can potentially indicate a long‐distance transport into new ecosystems with implications on toxicity and biodiversity. [ABSTRACT FROM AUTHOR]

Inorganic nutrient contents of mucus released by Acropora corals and its utilization by heterotrophic bacteria at several different hour intervals in the coral mucus were investigated at a coral reef in Malaysia. The dissolved inorganic phosphate ( DIP) concentration was 135-fold higher than in the ambient seawater, probably due to inorganic P release from the coral gut cavity. We experimentally confirmed that heterotrophic bacteria rapidly (within 8 h) consumed ca. 80% of the initial concentration of DIP derived from coral mucus. High DIP concentration in coral mucus may enhance heterotrophic bacterial production and associated carbon flow in the microbial loop of reef ecosystems. [ABSTRACT FROM AUTHOR]

Gelatinous zooplankton abundance and species composition were investigated at 3-h intervals for a 48-h period at a fringing reef in Malaysia. A total of 20 gelatinous zooplankton species were observed; the community was dominated by the calycophoran siphonophore Diphyes chamissonis (79.9%), followed by the trachymedusdae Aglaura hemistoma (5.6%) and Liriope tetraphylla (4.8%). The gelatinous zooplankton were not collected in the water column during most of the daytime hours (1200, 1500 and 1800 h) but were common during the night. However, an abrupt peak in abundance was found at 0900 h on the second day. The times of appearance at night were different depending on the species, and the number of species was also different depending on the hour of sampling. Sampling at 3-h intervals over a 48-h period revealed that the temporal variation (or sampling availability) was large in this study. Careful consideration should be given to the sampling variability in handling the gelatinous zooplankton samples in coral reef areas. [ABSTRACT FROM AUTHOR]

Quantitative research on composition, biomass and production rates of zooplankton community is crucial to understand the trophic structure in coral reef pelagic ecosystems. In the present study, micro- (35-100 μm) and net- (>100 μm) metazooplankton were investigated in a fringing coral reef at Tioman Island of Malaysia. Sampling was done during the day and night in August and October 2004, and February and June 2005. The mean biomass of total metazooplankton ( i.e. micro + net) was 3.42 ± 0.64 mg C·m−3, ranging from 2.32 ± 0.75 mg C·m−3 in October to 3.26 ± 1.77 mg C·m−3 in August. The net-zooplankton biomass exhibited a nocturnal increase from daytime at 131-264% due to the addition of both pelagic and reef-associated zooplankton into the water column. The estimated daily production rates of the total metazooplankton community were on average 1.80 ± 0.57 mg C·m−3·day−1, but this increased to 2.51 ± 1.06 mg C·m−3·day−1 if house production of larvaceans was taken into account. Of the total production rate, the secondary and tertiary production rates were 2.20 ± 1.03 and 0.30 ± 0.06 mg C·m−3·day−1, respectively. We estimated the food requirements of zooplankton in order to examine the trophic structure of the pelagic ecosystem. The secondary production may not be satisfied by phytoplankton alone in the study area and the shortfall may be supplied by other organic sources such as detritus. [ABSTRACT FROM AUTHOR]

This paper proposes a new type of indoor human detection system using UHF-band TV receiving waves (below referred to as “UHF-TV waves”). Due to the use of TV broadcasting waves as radio transmission sources, the proposed systems need no transmitter; the systems are composed only of receiving systems, including a receiving antenna and a receiver. The proposed systems can detect the presence or absence of humans in a room, based on the principle that the received levels fluctuate due to multipath fading or shadowing with human presence. It is noteworthy that the proposed systems utilize the indoor multipath radio propagations of broadcasting waves to detect the human presence. In order to investigate the capabilities of human detection systems using UHF-TV waves, we measured the received levels of UHF-TV waves in a room with or without human presence. Our proposed systems were able to detect a human presence by using an appropriate threshold of the received level fluctuation. The monitoring time of only 7 seconds allows 100% detection probability in the proposed detection system. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 90(10): 32–39, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjb.20378 [ABSTRACT FROM AUTHOR]

This study examines the practicality of M-quadrature amplitude modulation (M-QAM) where the number of signal points M is not a power of two. A practical problem is the complexity of the configuration because one symbol in an M-QAM signal does not correspond to an integer number of bits, and the symbol error does not simply convert to the bit error. Therefore, from the perspective of simplifying the configuration and minimizing bit error rate (BER) properties, multidimensional encoding (binary/M-ary conversion) for converting a binary sequence to correlated symbols is proposed and the theoretical formulas of the symbol error rate (SER) and the bit error rate (BER) are clarified. SER properties of 40QAM, 44QAM, 48QAM, 56QAM, and 60QAM fall between 32QAM and 64QAM. The configuration of a QAM scheme where the number of signal points becomes 3 × 2p-1 where p is an integer greater than or equal to 3 is shown, as are theoretical values for the SER properties of 12QAM and 24QAM in particular. Also shown are the theoretical values of the BER properties with and without differential encoding; these are verified with a computer simulation. A discussion based on these results concerns the effectiveness of M-QAM in the sense of expanding decision branches for adaptive modulation. © 2006 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 90(2): 46–57, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.20269 [ABSTRACT FROM AUTHOR]

Seismic electromagnetic (EM) phenomena have been observed at many laboratories with specially designed systems. Recently we can utilize radio receivers, personal computers, and communication systems with higher performances and reasonable cost. It is possible to observe seismic EM phenomena not only by specially designed systems but also by a simple observation system integrated by these devices and systems. We have created an observation system for seismic EM phenomena with them in the very high frequency (VHF) band, from 76 MHz to 90 MHz, assigned for FM broadcasting exclusive use in Japan. We are surrounded by many EM waves, such as broadcasting, communication usage, and man-made noises. Thus, we have newly developed the dual frequency observation method. In this paper, we describe an observation method that can identify whether a received signal is a broadband EM wave or an artificial FM radio wave. Next, the observation results for broadband EM waves from galactic noise and solar flares are presented. Then, the observation results for FM radio waves reflected from sporadic E layer and the Leonid meteors are shown. Finally, the observation results for the detected broadband EM waves associated with the Geiyo earthquake are described. © 2006 Wiley Periodicals, Inc. Electr Eng Jpn, 155(4): 36–44, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20350 [ABSTRACT FROM AUTHOR]

In the quasi-millimeter radio access system, the links are installed radially from the central station (CS) to the outstation (OS). Therefore, the interference characteristics of the CS are deteriorated at the time of rain. This paper process a transmission power control method with a view to reducing the deterioration of the interference charcteristics at the CS in rain. The effect of compensation of the level ratio of a desired wave to an undesired wave (D/U) degradation at the CS in the rain can be reduced by 11.5 dB by the transmission power control (TPC) of 20 dB. Further, the speed of the rain attenuation was found which is a propagation parameter needed for the TPC. The trailing speed of the rain attenuation in the proposed TPC algorithm is 67 dB/s, which is much larger than the maximum speed of the 3 dB/a of the rain attenuation. Hence, the proposed TPC algorithm can sufficiently follow the rain attenuation. [ABSTRACT FROM AUTHOR]

To realize high-capacity wireless access, the millimeter-wave frequencies have been investigated. Research on indoor multipath propagation has been pursued intensively. This paper proposes an evaluation method for the millimeter-wave indoor high-capacity digital transmission characteristics. First, the broadband propagation characteristics under indoor multipath environment were measured so that the multiple-wave configurations are clarified. Next, to quantify the digital transmission characteristics under the multiple wave environment, the level ratio (D/U) of the desired wave to the interference wave was evaluated for a bit error rate of 10-4 by means of a 4 PSK- 100 Mb/s and a multipath fading simulator. It was found that the bit error rate is determined by the level ratio (D/UT) of the desired wave to the total interference waves and not by the delay time of the interference wave if the delay time of the interference wave exceeds the symbol duration and that the desired D/UT approaches the signal-to-noise (S/N) ratio (N: Gaussian noise) giving such a bit error rate. From the foregoing results, this paper proposes a channel design method using the D/U in indoor high-capacity wireless communication. [ABSTRACT FROM AUTHOR]