57 research outputs found
A NEW ONISCOPSIS SPECIES (COPEPODA, HARPACTICOIDA) FOUND ON THE SANDY BEACH OF MUKAISHIMA ISLAND, THE INLAND SEA OF JAPAN
In this paper, a new species of the genus Oniscopsis Chappuis, 1954 (Copepoda, Harpacticoida, Tetragonicipitidae: see Becker and Kunz, 1981) is described on the basis of some male and female specimens from the interstices of beach sand in Mukaishima Island, the Inland Sea of Japan. The genus Oniscopsis is, at present, composed of two species: 0. pauliani Chappuis, 1954 and 0. robinsoni Chappuis & Delamare Deboutteville, 1956. This is the first record of this genus from Japan. The sampling station is situated midway between M.H.W.S. and M.H.W.N. on the beach (about 3.1 meters above the datum line), where the mean grain size is approximately 1.8 mm in diameter. The material was obtained from sand samples by means of the so-called decanting-sieving method. Dissected somites and appendages were mounted on slides using Sasa's gum-chloral medium. Slide preparations used for the description are indicated by numbers in parentheses. The surface structure of the integument was examined with a scanning electron microscope, JSM-25 (Japanese Electron Optics Lab.). All specimens examined are deposited in the Mukaishima Marine Biological Station, Hiroshima University. Before going further, I would like to express my sincere thanks to Professor Akihiko Inaba of the Mukaishima Marine Biological Station, Hiroshima University, for his support and guidance to the present study. Sincere thanks are also due to Professor F.E. Round of the Department of Botany, University of Bristol, who read the manuscript with good grace. I am also grateful to Dr. Tatsunori Ito of the Seto Marine Biological Laboratory, Kyoto University, for giving beneficial advices
Low-Cost Real-Time Gas Monitoring Using a Laser Plasma Induced by a Third Harmonic Q-Switched Nd-YAG Laser
A gas plasma induced by a third harmonic Nd-YAG laser with relatively low pulsed energy (about 10 mJ) has favorable characteristics for gas analysis due to its low background characteristics, nevertheless a high power fundamental Nd-YAG laser (100-200 mJ) is widely used for laser gas breakdown spectroscopy. The air plasma can be used as a low-cost real-time gas monitoring system such that it can be used to detect the local absolute humidity, while a helium plasma can be used for gas analysis with a high level of sensitivity. A new technique using a helium plasma to improve laser ablation emission spectroscopy is proposed. Namely, the third harmonic Nd-YAG laser is focused at a point located some distance from the target in the 1-atm helium surrounding gas. By using this method, the ablated vapor from the target is excited through helium atoms in a metastable state in the helium plasma
Enhanced FCM of a Nd:YAG Laser in CPM Operation
The pulsewidth of a flash -lamp pumped Nd: YAG laser in linear cavity is significantly shortened by joint operation of CPM (Colliding Mode-locking) and FCM Feedback Controlled Mode-locking). The CPM operation is done with a saturable absorber set at a quarter of the cavity length apart from the end mirror. Four pulses are generated simultaneously in the cavity These pulses collide in the saturable dye cell and also at another quarter apart from the coupling mirror. therfore, the FCM effect can be enhanced by pulse colliding in a GaAs wafer inserted at this position. On this joint operation,the duration of pulse train,in which the pulse interval is 2ns, is extended up to 80ns. The pulsewidth is shortened down to 3.3ps in Gaussian shape (3.Ops sech2),while the pulse energy is 7μJ
Measurements of Induced Transmission and Absorption-of SF6 after Pumped by a CO2 Laser (Ⅱ)-Spatial Evolution of Vibrational Energy -
The spatial distribution and dissipation of vibrational energy in SF6 gas after multiphoton
excitation was measured with the pump-probe technique by use of two tunable
TE C02 lasers. The probe beam (0.5mm radius) monitored the induced transmission
and absorption both inside and outside of the pumped region (0.6mm),or the in-axis and
off-axIs vibrational distribution. The vibrationally excited (hot) molecules are extended
over the radial distance of 3mm out of the the pumped region at the delay time of 50μs
after pumping. It was observed that the probed spectra and time behavior of the off-axis
absorption was quite different from that of the in-axis. The vibrational temperature of
the off-axis molecules seems much lower than that of the in-axis. Thus,it is considered
that the surrounding molecules are sufficiently excited by the T-V collisional process due
to the gas expansion out of the pumped region rapidly heated up by the V-T relaxation.
The effects of gas pressure,additive gas (He,N2 )and pump intensity were also studied
Neurospora from natural populations: Population genomics insights into the Life history of a model microbial Eukaryote
The ascomycete filamentous fungus Neurospora crassa played a historic role in experimental biology and became a model system for genetic research. Stimulated by a systematic effort to collect wild strains initiated by Stanford geneticist David Perkins, the genus Neurospora has also become a basic model for the study of evolutionary processes, speciation, and population biology. In this chapter, we will first trace the history that brought Neurospora into the era of population genomics. We will then cover the major contributions of population genomic investigations using Neurospora to our understanding of microbial biogeography and speciation, and review recent work using population genomics and genome-wide association mapping that illustrates the unique potential of Neurospora as a model for identifying the genetic basis of (potentially adaptive) phenotypes in filamentous fungi. The advent of population genomics has contributed to firmly establish Neurospora as a complete model system and we hope our review will entice biologists to include Neurospora in their research
THREE NEW SPECIES OF THE GENUS PHYLLOPODOPSYLLUS (COPEPODA, HARPACTICOIDA) FROM THE INLAND SEA OF JAPAN
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