The abundance and bacterivory of heterotrophic nanoflagellates (HNF) were seasonally followed in the oxic and anoxic layers of the meromictic Lake Suigetsu between May 2008 and November 2010. The HNF ...abundance in the anoxic layer was always lower than in the oxic layer during the study period. Ingestion of fluorescently labeled 0.5 mu m diameter beads by the anaerobic HNF in the anoxic layer indicated bacterivory by HNF. The specific ingestion rates in the anoxic layers were generally similar to those taken from the oxic layer, with some exceptions. Our data thus suggested that anaerobic HNF were bacterial consumers with high potential bacterivory comparable to that of aerobic HNF in Lake Suigetsu. Bacterial turnover rates by HNF grazing in the oxic layer were estimated to be as high as similar to 10% d super(-1) of the bacterial standing stock. In contrast, the rates in the anoxic layer were <1% d super(-1) due to the low density of HNF in the anoxic layer. Our data thus provide a valuable contribution to understanding the structure and function of microbial food webs in anoxic aquatic environments.
Primordial gravitational waves generated by inflation have produced an odd-parity pattern B-mode in the cosmic microwave background (CMB) polarization. LiteBIRD (Light satellite for the studies of ...B-mode polarization and Inflation from cosmic background Radiation Detection) aims at detecting this B-mode polarization precisely. It requires about 2000 detectors capable of detecting a frequency range from 50GHz to 250GHz with ultra low noise. Superconducting detectors are suitable for this requirement. We have fabricated and tested microwave kinetic inductance detectors (MKIDs) and developed a new readout system.
We have designed antenna-coupled MKIDs. Quasi-particles are created by incident radiation and are detected as a change of the surface impedance of a superconductor strip. This change of the surface impedance is translated into the change of the resonant frequency of a microwave signal transmitted through the resonator.
We also have developed a new readout system for MKIDs. The newly developed readout system is not only able to read out the amplitude and the phase data with the homodyne detection for multi-channels, but also provides a unique feature of tracking the resonant frequency of the target resonator. This mechanism enables us to detect signals with a large dynamic range. We report on the recent R&D status of the developing MKIDs and on the read-out system for LiteBIRD.
Tumor protein p53 gene and its negative regulator, murine double minute 2 homolog are important components for cell-cycle arrest and apoptosis. An arginine-to-proline substitution at codon 72 in the ...p53 gene is reported to decrease apoptotic potential, while a thymine-to-guanine polymorphism at nucleotide 309, named SNP309, of murine double minute 2 gene increases transcription of the gene. These two polymorphisms therefore may be of importance in colorectal carcinogenesis. The relation of these polymorphisms to colorectal cancer risk was addressed in the Fukuoka Colorectal Cancer Study.
We genotyped the two polymorphisms in 685 incident cases of colorectal cancer and 778 community controls by the polymerase chain reaction-restriction fragment length polymorphism method. Statistical adjustment was made for sex and age.
The proline allele of p53 gene and the guanine allele of SNP309 were each associated with a small, statistically non-significant increase in the odds ratio of colorectal cancer; the adjusted odds ratio (95% confidence interval) for arginine/proline and proline/proline genotypes combined versus arginine/arginine genotype of p53 gene was 1.23 (0.99-1.52) and that for thymine/guanine and guanine/guanine genotypes combined versus thymine/thymine genotype of SNP309 was 1.27 (0.98-1.63). Individuals harboring the proline allele of p53 gene and the guanine allele of SNP309 showed an odds ratio of 1.67 (95% confidence interval, 1.11-2.51).
Codon 72 polymorphism of p53 and SNP309 in combination may confer an increased risk of colorectal cancer.
The conduction-cooled superconducting magnets are now widely used in various applications due to their minimum usage of helium. In the accelerator science, they also play an increasingly important ...role in particle detector solenoids because they can minimize the materials needed for the magnet such that they can be more transparent against irradiated particles. For the same reason they are currently used in high radiation environments because they can reduce the heat load from the irradiation. However, the hadronic reactions, such as neutron or proton irradiation, can create degradation on the thermal conductivity of pure aluminum which is used as a cooling path. It leads to a poor cooling condition of the magnets. In Japan, there are two conduction-cooled superconducting magnets for muon production; one is already constructed and under operation, the other is now under construction. This paper briefly reports the influence of the irradiation on those magnets and discusses the possibilities of HTS based conduction-cooled magnets under high irradiation environments.
Precise measurement of the muonium hyperfine structure (MuHFS) has been planned at J-PARC. The key component of this experiment is a superconducting solenoid magnet with field homogeneity as high as ...1 ppm. In this paper, we focus on the cryogenic design of this magnet. The total heat input to the magnet system was estimated and a combination of cryocoolers was determined. To reduce the heat leakage to 4 K, the structure of a He exhaust pipe and different arrangements of the baffles were considered. Based on the ray-trace model, radiation heat input through a bent pipe was calculated. A cooling test was carried out for the current lead. We confirmed that the polyimide tape-insulated Cu lead with an applied current of 400 A can be conduction-cooled with temperature difference of 5 K from the cold stage of a cryocooler. Mechanical vibration is a critical issue to achieve the required field homogeneity. We have also started vibration measurements using a He re-condensation cryostat to consider support structure of the coils.
After a magnitude 7.2 earthquake in 1975 and before the start of the ongoing eruption in 1983, deformation of Kilauea volcano was the most rapid ever recorded. Three-dimensional numerical modeling ...shows that this deformation is consistent with the dilation of a dike within Kilauea's rift zones coupled with creep over a narrow area of a low-angle fault beneath the south flank. Magma supply is estimated to be 0.18 cubic kilometers per year, twice that of previous estimates. The 1983 eruption may be a direct consequence of the high rates of magma storage within the rift zone that followed the 1975 earthquake.
Although brain cell viability depends largely on cerebral circulation, mechanisms of blood flow control, such as autoregulation, or of the pathogenesis of functionally impaired blood supply to brain ...regions, such as in cerebral vasospasm after subarachnoid hemorrhage, have not been clearly defined. Our recent studies support the hypothesis that nitric oxide, released from nitrergic nerves, plays a crucial role as a neurotransmitter in vasodilating cerebral arteries from primate and subprimate mammals. In the present study, we demonstrated, by using arterial angiography, that electrical stimulation of the pterygopalatine ganglion produced vasodilatation of ipsilateral cerebral arteries of anesthetized Japanese monkeys. The response was abolished by intravenous injections of
N
G-nitro-
l-arginine, a nitric oxide synthase inhibitor. Denervation of the ganglion elicited cerebral vasoconstriction, indicating that vasodilator nerves from the vasomotor center were tonically active. Stimulation of the greater petrosal nerve, upstream of the pterygopalatine ganglion, also elicited cerebral vasodilatation, which was abolished by treatment with the nitric oxide synthase inhibitor and with hexamethonium, indicating that the nerve is in connection via synapses with the nitrergic nerve innervating cerebral arteries. Endogenous nitric oxide released from the nerve may contribute to the maintenance of blood flow in major cerebral arteries necessary to supply blood to the different brain regions. Without this influence, cerebral arteries might be constricted to the extent that blood flow is impeded.
This is the first direct evidence indicating an important role of nitric oxide liberated by pre- and postganglionic nerve stimulation in the control of cerebral arterial tone in primates.
BACKGROUND: C-reactive protein (CRP) and many fatty acids (FAs) have been linked to cardiovascular disease. Associations of serum CRP with FAs in different populations have not been established. ...METHODS: Participants were 926 men aged 40-49 (2002-2006) from a population-based sample; 310 Whites from Pennsylvania, U.S., 313 Japanese from Shiga, Japan, and 303 Japanese Americans from Hawaii, U.S. Serum CRP (mg/L) was measured using immunosorbent assay while serum FAs (%) were measured using capillary-gasliquid chromatography. RESULTS: Whites had CRP (mg/L) levels higher than Japanese with Japanese Americans in-between (age-adjusted geometric mean “GM” 0.96, 0.38, 0.66, respectively). Whites had also higher levels of total n-6 FAs (%) and trans fatty acids (TFAs) but lower levels of marine-derived n-3 FAs compared to Japanese (41.78 vs. 35.05, 1.04 vs. 0.58, & 3.85 vs. 9.29, respectively). Japanese Americans had FAs levels in-between the other two populations. Whites had significant inverse trends between CRP and tertiles of total n-6 FAs (GM 1.20, 0.91 & 0.80; p=0.002) and marine-derived n-3 FAs (GM 1.22, 1.00 & 0.72; p<0.001) but a significant positive trend with TFAs (GM 0.80, 0.95 & 1.15; p=0.007). Japanese had a significant inverse trend between CRP and only total n-6 FAs (GM 0.50, 0.35 & 0.31; p<0.001). Japanese Americans had CRP associations with n-3 FAs, n-6 FAs, and TFAs similar to but weaker than Whites. CONCLUSIONS: With the exception of consistent inverse association of CRP with total n-6 FAs, there are considerable variations across the three populations in the associations of CRP with different FAs.
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