417 research outputs found
Fish assemblages associated with three types of artificial reefs: density of assemblages and possible impacts on adjacent fish abundance
We evaluated the effectiveness of wooden artificial reefs (ARs) as fish habitat. Three types of ARs, made of cedar logs, broadleaf tree logs, and PVC pipes, respectively,
were deployed in triplicate at 8-m depth off Maizuru, Kyoto Prefecture, Sea of Japan, in May 2004. Fish assemblages associated with each of the nine ARs were observed by using
SCUBA twice a month for four years. Fish assemblages in the adjacent habitat were also monitored for two years before and four years after reef deployment. In the surveyed areas
(ca. 10 m2) associated with each of the cedar, broadleaf, and PVC ARs, the average number of fish species was 4.14, 3.49, and 3.00, and the average number of individuals was 40.7, 27.9, and 20.3, respectively. The estimated biomass was also more greater when associated with the cedar ARs than with other ARs. Visual censuses of the habitat adjacent to the ARs revealed that the number of fish species and the density of individuals were not affected by the deployment of the ARs. Our results support the superiority of cedar as an AR material and indicate that deployment of wooden ARs causes no reduction of fish abundance in adjacent natural reefs
Acoustic HMMs to Detect Abnormal Respiration with Limited Training Data
In many situations, abnormal sounds, called adventitious sounds, are included with the lung sounds of a subject suffering from pulmonary diseases. Thus, a method to automatically detect abnormal sounds in auscultation was proposed. The acoustic features of normal lung sounds for control subjects and abnormal lung sounds for patients are expressed using hidden markov models (HMMs) to distinguish between normal and abnormal lung sounds. Furthermore, abnormal sounds were detected in a noisy environment, including heart sounds, using a heart-sound model. However, the F1-score obtained in detecting abnormal respiration was low (0.8493). Moreover, the duration and acoustic properties of segments of respiratory, heart, and adventitious sounds varied. In our previous method, the appropriate HMMs for the heart and adventitious sound segments were constructed. Although the properties of the types of adventitious sounds varied, an appropriate topology for each type was not considered. In this study, appropriate HMMs for the segments of each type of adventitious sound and other segments were constructed. The F1-score was increased (0.8726) by selecting a suitable topology for each segment. The results demonstrate the effectiveness of the proposed method
Isolation of a transcriptionally active element of high copy number retrotransposons in sweetpotato genome
Many plant retrotransposons have been characterized, but only three families (Tnt1, Tto1 and
Tos17) have been demonstrated to be transpositionally competent. We followed a novel approach
that enabled us to identify an active element of the Ty1-copia retrotransposon family with
estimated 400 copies in the sweetpotato genome. DNA sequences of Ty1 -copia reverse
transcriptase (RTase) from the sweetpotato genome were analyzed, and a group of
retrotransposon copies probably formed by recent transposition events was further analyzed.
3’RACE on callus cDNA amplified transcripts containing long terminal repeats (LTR) of this
group. The sequence -specific amplification polymorphism (S-SAP) patterns of the LTR sequence
in the genomic DNA were compared between a normal plant and callus lines derived from it. A
callus -specific S-SAP product was found into which the retrotransposon detected by the 3’RACE
had been transposed apparently during cell culture. We conclude that our approach provides an
effective way to identify active elements of retrotransposons with high copy numbers.</p
STM Observation of the Si(111) - (7×7) Reconstructed Surface Modified by Excess Phosphorus Doping
The electronic properties of semiconductor surfaces change readily upon changing the carrier densities by controlling the dopant concentration. Additionally, excess dopant atoms can exert electric field which would affect the molecular adsorption process and could be used to manipulate the dynamic movement of confined molecules. A mechanism can be developed to control the molecular dynamic movement on modified semiconductor surface by dopants thus changing the effect of the electric field on the active molecules. In this study, the Si(111) surface was doped with phosphorus excessively using thermal diffusion process. The surface was then reconstructed to the 7 × 7 configuration via heating under UHV conditions and then studied through STM and STS techniques. The protrusions due to surface and subsurface P atoms appear brighter due to the lone electron pair. The 7 × 7 reconstruction would be destabilized after a critical P substitution of Si-adatom concentration due to high surface strain result in P-terminated (6√3 × 6√3)R30º reconstruction
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Surface tension measurement of glass melts by the maximum bubble pressure method
The maximum bubble pressure method was used to obtain accurate surface tension measurements. The dependence of apparent surface tension value on bubble growth time was measured for times from several to longer than a thousand seconds. The static surface tension value was obtained by extrapolating bubble growth time to infinity. The dynamic surface tension, which is familiar in colloids, could not be directly obtained because of the high viscosity of glass melt. The effects of capillary tip material and shape were also examined. This method is applicable to melts with viscosity less than 10^3.5 dPa s. The reproducibility in the measurement was within a few percent
Discrimination between healthy subjects and patients with pulmonary emphysema by detection of abnormal respiration
In this paper, we propose a robust classification strategy for distinguishing between a healthy subject and a patient with pulmonary emphysema on the basis of lung sounds. A symptom of pulmonary emphysema is that almost all lung sounds include some abnormal (i.e., adventitious) sounds. However, the great variety of possible adventitious sounds and noises at auscultation makes high-accuracy detection difficult. To overcome this difficulty, our strategy is to adopt a two-step classification approach based on the detection of "confident abnormal respiration." In the first step, hidden Markov models and bigram models are used for acoustic features and the occurrence of acoustic segments in each abnormal respiratory period, respectively, to calculate two kinds of stochastic likelihoods: the highest likelihood for a segment sequence to be abnormal respiration and the likelihood for normal respiration. In the second step, the patients are identified on the basis of the detection of confident abnormal respiration, which is when difference between these two likelihoods is larger than a predefined threshold. Our strategy achieved the highest classification rate of 88.7% between healthy subjects and patients among three basic classification strategies, which shows the validity of our approach.ICASSP 2011 - 2011 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP) : Prague, Czech Republic, 2011.05.22-2011.05.2
Development of an energy and environmental education program dealing with social issues
In the 3rd grader of junior high school, we propose a new subject "resources and energy" dealing with social issues. Through this subject, we aim to foster the ability to think from a multifaceted and integrated viewpoint. We conducted a questionnaire survey whether students understand about scientific or social terms related to energy in the next year. The degree of understanding of the students who learned the program was high. And there were many students who thought that social issues could be solved by science and technology in future in comparison with groups that did not study this program
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