The Simons Observatory: Cryogenic half wave plate rotation mechanism for the small aperture telescopes.

We present the requirements, design, and evaluation of the cryogenic continuously rotating half-wave plate (CHWP) for the Simons Observatory (SO). SO is a cosmic microwave background polarization experiment at Parque Astronómico de Atacama in northern Chile that covers a wide range of angular scales using both small (⌀0.42 m) and large (⌀6 m) aperture telescopes. In particular, the small aperture telescopes (SATs) focus on large angular scales for primordial B-mode polarization. To this end, the SATs employ a CHWP to modulate the polarization of the incident light at 8 Hz, suppressing atmospheric 1/f noise and mitigating systematic uncertainties that would otherwise arise due to the differential response of detectors sensitive to orthogonal polarizations. The CHWP consists of a 505 mm diameter achromatic sapphire HWP and a cryogenic rotation mechanism, both of which are cooled down to ∼50 K to reduce detector thermal loading. Under normal operation, the HWP is suspended by a superconducting magnetic bearing and rotates with a constant 2 Hz frequency, controlled by an electromagnetic synchronous motor. We find that the number of superconductors and the number of magnets that make up the superconducting magnetic bearing are important design parameters, especially for the rotation mechanism's vibration performance. The rotation angle is detected through an angular encoder with a noise level of 0.07 µrad s. During a cooldown process, the rotor is held in place by a grip-and-release mechanism that serves as both an alignment device and a thermal path. In this paper, we provide an overview of the SO SAT CHWP: its requirements, hardware design, and laboratory performance.

Nuclear and magnetic spin structure of the antiferromagnetic triangular lattice compound LiCrTe2 investigated by [Formula: see text]SR, neutron and X-ray diffraction.

Two-dimensional (2D) triangular lattice antiferromagnets (2D-TLA) often manifest intriguing physical and technological properties, due to the strong interplay between lattice geometry and electronic properties. The recently synthesized 2-dimensional transition metal dichalcogenide LiCrTe[Formula: see text], being a 2D-TLA, enriched the range of materials which can present such properties. In this work, muon spin rotation ([Formula: see text]SR) and neutron powder diffraction (NPD) have been utilized to reveal the true magnetic nature and ground state of LiCrTe[Formula: see text]. From high-resolution NPD the magnetic spin order at base-temperature is not, as previously suggested, helical, but rather collinear antiferromagnetic (AFM) with ferromagnetic (FM) spin coupling within the ab-plane and AFM coupling along the c-axis. The value if the ordered magnetic Cr moment is established as [Formula: see text]. From detailed [Formula: see text]SR measurements we observe an AFM ordering temperature [Formula: see text] K. This value is remarkably higher than the one previously reported by magnetic bulk measurements. From [Formula: see text]SR we are able to extract the magnetic order parameter, whose critical exponent allows us to categorize LiCrTe[Formula: see text] in the 3D Heisenberg AFM universality class. Finally, by combining our magnetic studies with high-resolution synchrotron X-ray diffraction (XRD), we find a clear coupling between the nuclear and magnetic spin lattices. This suggests the possibility for a strong magnon-phonon coupling, similar to what has been previously observed in the closely related compound LiCrO[Formula: see text].

Bi-Arrhenius Diffusion and Surface Trapping of

We report measurements of the diffusion rate of isolated ion-implanted ^{8}Li^{+} within ∼120 nm of the surface of oriented single-crystal rutile TiO_{2} using a radiotracer technique. The α particles from the ^{8}Li decay provide a sensitive monitor of the distance from the surface and how the depth profile of ^{8}Li evolves with time. The main findings are that the implanted Li^{+} diffuses and traps at the (001) surface. The T dependence of the diffusivity is described by a bi-Arrhenius expression with activation energies of 0.3341(21) eV above 200 K, whereas at lower temperatures it has a much smaller barrier of 0.0313(15) eV. We consider possible origins for the surface trapping, as well the nature of the low-T barrier.

Immunosuppression through constitutively activated NF-κB signalling in human ovarian cancer and its reversal by an NF-κB inhibitor.

BACKGROUND: Although T-cell immunity is thought to be involved in the prognosis of epithelial ovarian cancer (EOC) patients, immunosuppressive conditions hamper antitumour immune responses. Thus, their mechanisms and overcoming strategies need to be investigated. METHODS: The role of NF-κB in human EOC cells and macrophages was evaluated by in vitro production of immunosuppressive IL-6 and IL-8 by EOC cells and in vivo analysis of immune responses in nude mice implanted with human EOC cells using an NF-κB inhibitor DHMEQ. RESULTS: In EOC patients, increased plasma IL-6, IL-8, and arginase were observed. The NF-κB inhibitor DHMEQ inhibited the production of IL-6 and IL-8 by EOC cell lines. Immunosuppression of human DCs and macrophages by culture supernatant of EOC cells was reversed with the pretreatment of DHMEQ. Administration of DHMEQ to nude mice implanted with human EOC resulted in the restoration of T-cell stimulatory activity of murine DCs along with the reduction of tumour accumulation and arginase expression of MDSCs. Nuclear factor-κB inhibition in tumour-bearing mice also enhanced antitumour effects of transferred murine naive T cells. CONCLUSIONS: NF-κB is involved in the immunosuppression induced by human EOC, and its inhibitor may restore antitumour immune responses, indicating that NF-κB is an attractive target for EOC treatment.

1D to 2D Na+ ion diffusion inherently linked to structural transitions in Na0.7CoO2.

We report the observation of a stepwise "melting" of the low-temperature Na-vacancy order in the layered transition-metal oxide Na0.7CoO2. High-resolution neutron powder diffraction analysis indicates the existence of two first-order structural transitions, one at T1≈290 K followed by a second at T2≈400 K. Detailed analysis strongly suggests that both transitions are linked to changes in the Na mobility. Our data are consistent with a two-step disappearance of Na-vacancy order through the successive opening of first quasi-1D (T1>T>T2) and then 2D (T>T2) Na diffusion paths. These results shed new light on previous, seemingly incompatible, experimental interpretations regarding the relationship between Na-vacancy order and Na dynamics in this material. They also represent an important step towards the tuning of physical properties and the design of tailored functional materials through an improved control and understanding of ionic diffusion.

Non-destructive evaluation of ATP content and plate count on pork meat surface by fluorescence spectroscopy.

The potential of fluorescence spectroscopy was investigated for the non-destructive evaluation of ATP content and plate count on pork meat surface stored aerobically at 15 °C during three days. Excitation (Ex) Emission (Em) Matrix of fluorescence intensity was obtained and fluorescence from tryptophan (Ex=295 nm and Em=335 nm) and NADPH (Ex=335 nm and Em=450 nm) was detected. Because tryptophan and NADPH fluorescence changed along with the growth of microorganisms, microbial spoilage on meat could be detected from fluorescence. By applying PLSR (Partial Least Squares Regression) analysis, ATP content and plate count were predicted with good determination coefficient (0.94-0.97 in calibration and 0.84-0.88 in validation).

Ectopic expression of cone-specific G-protein-coupled receptor kinase GRK7 in zebrafish rods leads to lower photosensitivity and altered responses.

To investigate the roles of G-protein receptor kinases (GRKs) in the light responses of vertebrate photoreceptors, we generated transgenic zebrafish lines, the rods of which express either cone GRK (GRK7) or rod GRK (GRK1) in addition to the endogenous GRK1, and we then measured the electrophysiological characteristics of single-cell responses and the behavioural responses of intact animals. Our study establishes the zebrafish expression system as a convenient platform for the investigation of specific components of the phototransduction cascade. The addition of GRK1 led to minor changes in rod responses. However, exogenous GRK7 in GRK7-tg animals led to lowered rod sensitivity, as occurs in cones, but surprisingly to slower response kinetics. Examination of responses to long series of very dim flashes suggested the possibility that the GRK7-tg rods generated two classes of single-photon response, perhaps corresponding to the interaction of activated rhodopsin with GRK1 (giving a standard response) or with GRK7(giving a very small response). Behavioural measurement of optokinetic responses (OKR) in intact GRK7-tg zebrafish larvae showed that the overall rod visual pathway was less sensitive, in accord with the lowered sensitivity of the rods. These results help provide an understanding for the molecular basis of the electrophysiological differences between cones and rods.

Detection of a new parametric decay instability branch in TST-2 during high harmonic fast wave heating.

Parametric decay instability (PDI) is often observed in the TST-2 spherical tokamak during high harmonic fast wave heating by rf pickup probes. The frequency spectrum exhibits lower and upper sideband peaks in addition to the pump wave at f(0)=21 MHz. Two types of PDI are observed. One is the well-known decay into the ion-cyclotron quasimode (nf(ci)) and the ion Bernstein wave (f(0)-nf(ci)). The other is a newly found decay with the sideband frequency between f(0) and f(0)-f(ci). The frequency difference between this sideband and the pump increases in proportion to B(t). Moreover, high-speed visible light measuring systems with photomultiplier tubes or hybrid photodetectors viewing the plasma core detected oscillation of light emission at around f(0).

Magnetic phase diagram of layered cobalt dioxide LixCoO2.

The magnetism of LixCoO2 (LCO), which has a similar structure to NaxCoO2 (NCO), has been investigated by muon-spin spectroscopy and susceptibility measurements using samples with x=0.1-1 prepared by an electrochemical reaction. In the x range below 0.75, LCO was found to be Pauli paramagnetic down to 1.8 K, suggesting an intermediate- or weak-coupling regime, although disordered local moments, with volume fractions below approximately 20%, appear at low T for LCO with x > or = 0.5. The phase diagram and interactions of LCO are thus strikingly different from NCO, while the differences cannot be explained simply by structural differences between the two systems.

Evidence of two dimensionality in quasi-one-dimensional cobalt oxides.

The quasi-one-dimensional (Q1D) cobalt oxides A(N + 2)Co(n + 1)O(3n + 3) (A = Ca, Sr, and Ba, n = 1 - infinity) were investigated by muon-spin spectroscopy under applied pressures of up to 1.1 GPa. The relationship between the onset Néel temperature T(on)(N) and the interchain distance (d(ic)), which increases monotonically with n, is well fitted by the formula T(N)/T(N,0) = (1 - d(ic)/d(ic,o)(beta), here for T(on)(N) approximately 100 K for Ca(3)Co(2)O(6) (n = 1) and approximately 15 for BaCoCoO(3) (n = infinity at ambient P. The T(on)(N) - d(ic) curve also predicts a large dependence of Y(N) for the compounds with n > or = 5, i.e., in the vicinity of , while the compounds show only a very small effect. Indeed, our high-pressure mu(+) results show that of BaCoO(3) is enhanced by with a slope of 2.2 K(Gpa), whereas no detectable changes by P for both Ca(3)Co(2)O(6) and Sr(4)Co(3)O(9) (n = 2). This clearly confirms the role of the 2D-antiferromagnetic interaction on T(on)(N) in the Q1D cobalt oxides.

Static magnetic order in metallic K0.49CoO2.

By means of muon-spin spectroscopy, we have found that K0.49CoO2 crystals undergo successive magnetic transitions from a high-T paramagnetic state to a magnetic ordered state below 60 K and then to a second ordered state below 16 K, even though K0.49CoO2 is metallic at least down to 4 K. An isotropic magnetic behavior and wide internal-field distributions suggest the formation of a commensurate helical spin density wave (SDW) state below 16 K, while a linear SDW state is likely to exist above 16 K. It was also found that exhibits a further transition at 150 K presumably due to a change in the spin state of the Co ions. Since the dependence of the internal-field below 60 K was similar to that for Na0.5CoO2, this suggests that magnetic order is more strongly affected by the Co valence than by the interlayer distance or interaction and/or the charge ordering.

Dome-shaped magnetic phase diagram of thermoelectric layered cobaltites.

Using muon spin spectroscopy we have found that, for both NaxCoO(2) (0.6

Tracking of a bronchoscope using epipolar geometry analysis and intensity-based image registration of real and virtual endoscopic images.

This paper describes a method for tracking the camera motion of a flexible endoscope, in particular a bronchoscope, using epipolar geometry analysis and intensity-based image registration. The method proposed here does not use a positional sensor attached to the endoscope. Instead, it tracks camera motion using real endoscopic (RE) video images obtained at the time of the procedure and X-ray CT images acquired before the endoscopic examination. A virtual endoscope system (VES) is used for generating virtual endoscopic (VE) images. The basic idea of this tracking method is to find the viewpoint and view direction of the VES that maximizes a similarity measure between the VE and RE images. To assist the parameter search process, camera motion is also computed directly from epipolar geometry analysis of the RE video images. The complete method consists of two steps: (a) rough estimation using epipolar geometry analysis and (b) precise estimation using intensity-based image registration. In the rough registration process, the method computes camera motion from optical flow patterns between two consecutive RE video image frames using epipolar geometry analysis. In the image registration stage, we search for the VES viewing parameters that generate the VE image that is most similar to the current RE image. The correlation coefficient and the mean square intensity difference are used for measuring image similarity. The result obtained in the rough estimation process is used for restricting the parameter search area. We applied the method to bronchoscopic video image data from three patients who had chest CT images. The method successfully tracked camera motion for about 600 consecutive frames in the best case. Visual inspection suggests that the tracking is sufficiently accurate for clinical use. Tracking results obtained by performing the method without the epipolar geometry analysis step were substantially worse. Although the method required about 20 s to process one frame, the results demonstrate the potential of image-based tracking for use in an endoscope navigation system.

A rapid bioluminescent enzyme immunoassay (BLEIA) for the detection of Shiga toxin types 1 and 2.

In recent years, Escherichia coli O157: H7 has emerged as a global public health concern. Among the more important virulence characteristics of this strain is its ability to produce one or more Shiga toxins (Stx). Traditional culture-based methods for assay of enteric toxins in foods and clinical samples are relatively slow and results can be ambiguous. In this work, we established a toxin-detection system based on bioluminescent enzyme immunoassay (BLEIA) using a simple and inexpensive device. The system could detect both Shiga toxin types 1 and 2 individually within 150 min with a detection limit for each toxin at 5 pg/ml. In our study of previously characterized Shigatoxigenic and all non-Shigatoxigenic E. coli and other bacterial species, we found all Shigatoxigenic strains to be positive and non-Shigatoxigenic E. coli and other bacterial species to be negative. This assay was also used to detect Stxs in milk and supernatant fluids from minced chicken and beef. For clinical stool samples we noted a tendency for the system to give unexpectedly high background level. Our results suggest the feasibility of using BLEIA methodology for the simple, rapid and sensitive detection of toxins from culture supernatant, various foods and clinical samples.

Roles of the exposed aromatic residues in crystalline chitin hydrolysis by chitinase A from Serratia marcescens 2170.

Four exposed aromatic residues, two in the N-terminal domain (Trp-69 and Trp-33) and two in the catalytic domain (Trp-245 and Phe-232) of Serratia marcescens chitinase A, are linearly aligned with the deep catalytic cleft. To investigate the importance of these residues in the binding activity and hydrolyzing activity against insoluble chitin, site-directed mutagenesis to alanine was carried out. The substitution of Trp-69, Trp-33, or Trp-245 significantly reduced the binding activity to both highly crystalline beta-chitin and colloidal chitin. The substitution of Phe-232, which is located closest to the catalytic cleft, did not affect the binding activity. On the other hand, the hydrolyzing activity against beta-chitin microfibrils was significantly reduced by the substitution of any one of the four aromatic residues including Phe-232. None of the mutations reduced the hydrolyzing activity against soluble substrates. These results clearly demonstrate that the four exposed aromatic residues are essential determinants for crystalline chitin hydrolysis. Three of them, two in the N-terminal domain and one in the catalytic domain, play vital roles in the chitin binding. Phe-232 appeared to be important for guiding the chitin chain into the catalytic cleft. Based on these observations, a model for processive hydrolysis of crystalline chitin by chitinase A is proposed.

Evidence for polyphyletic origin of the members of the orders of Oscillatoriales and Pleurocapsales as determined by 16S rDNA analysis.

Phylogenetic analyses were carried out on six pleurocapsalean strains and 12 oscillatorialean strains by sequence determination of the 16S rDNA (16S rRNA gene). Although heterocyst-forming strains of the orders Nostocales and Stigonematales were shown to be monophyletic, unicellular strains of the orders Chroococcales and filamentous Oscillatoriales were shown to be polyphyletic, as reported earlier. Moreover, unicellular and baeocyte-forming strains of the order Pleurocapsales, which were thought to be monophyletic, were newly found to be polyphyletic. The results strongly indicate that even morphology was not necessarily reflected in the phylogenetic relationships at the order level. A need exists to reconstruct the taxonomy of cyanobacteria at the order level.

Trp122 and Trp134 on the surface of the catalytic domain are essential for crystalline chitin hydrolysis by Bacillus circulans chitinase A1.

From the 3D-structural analysis of the catalytic domain of chitinase A1, two exposed tryptophan residues (W122 and W134) are proposed to play an important role in guiding a chitin chain into the catalytic cleft during the crystalline chitin hydrolysis. Mutation of either W122 or W134 to alanine significantly reduced the hydrolyzing activity against highly crystalline beta-chitin microfibrils. Double mutation almost completely abolished the hydrolyzing activity. On the other hand, the hydrolyzing activity against either soluble or amorphous substrate was not reduced. These mutations slightly impaired the binding activity of this enzyme. These results clearly demonstrated that the two exposed aromatic residues play a critical role in hydrolyzing the chitin chain in crystalline chitin.

Advanced technique for three-dimensional visualization of compound distributions in a rice kernel.

A three-dimensional (3D) visualization technique for the compound distribution in a rice kernel was developed. This technique is a combination of sectioning, staining, and digital image postprocessing. By using a special microtome system with adhesive tapes, a set of sequential sections of a rice kernel, which can be preserved with their own set of relative position data, was obtained. A single set of sequential sections was stained by various chemical techniques for the visualization of protein, starch, or lipid content. Each stained section was digitally captured using a CCD imaging device. As the stained areas represent areas containing dye-target complex, the distribution of each compound in the section was visualized in two dimensions. The digitally captured images of a single set of sequential sections were reconstructed to produce a 3D plotting image. As a result, the distributions of various compounds in a rice kernel could be visualized in a new 3D model.

[A role of visiting nurses in providing the terminal patients with their desirable life-discussion regarding the place of death of the patients who were registered for visiting nurse system].

AIM: To evaluate the prognosis of the patients who had visiting nurse service and discuss the place of death (life at the terminal stage). To determine the roles of visiting nurses in providing the patients at a terminal stage with their desirable life till death. METHODS: A total of 180 patients, who were registered for their home healthcare service in our Shonan Kamakura General Hospital and died between January 2000 and February 2001, were subjected to the study. All the subjects were classified into 3 groups according to the places of their death, 1) death at home, 2) death in the hospital and 3) death upon arrival after the admission to the hospital. Moreover, the following items were also surveyed and analyzed: 1) diagnosis (name of diseases), 2) cause of death, 3) age, 4) family structure, 5) whether their primary care physicians explained the prognosis and possible expected conditions to the patients and their family before hand, and 6) how the visiting nurses interact with the patients and their family members. RESULTS: Sixty-six patients died at home, 105 in the hospital and 9 upon arrival at the hospital. During this survey period, there were a total of 5,274 and 5,574 visits by primary care physicians and visiting nurses, respectively. The patients who died at home were more often observed in the patients whose primary care physicians explained their conditions to them and whose visiting nurses closely related to them. Moreover, the patients with malignant tumor also more often died at home. On the contrary, there were very few patients with chronic diseases, with whom death at home was accepted and agreed before hand, and there were some cases with chronic diseases who died inside of the ambulance transported on the way to the hospital after a sudden change in their conditions. DISCUSSION AND CONCLUSION: In order to have the patients live their desirable life till their death, it is required for the caretakers to prepare their mind for the day of the patient's death in addition to the patient's own wishes. For the patients with malignant tumor, it is easy to predict their prognosis, thus the caretakers can get prepared for the day of the patient's death. On the contrary, in case of the patients with chronic diseases, it is more difficult for the caretakers to experience an indefinite time with the patients since their prognosis is generally longer but the sudden change in their conditions may give the caretakers a high anxiety. Thus, it is essential for the visiting nurses to play a role as a mediator to interact between the patients and their family members, and their primary care physicians, and to establish a trustful relationship with the patients while their conditions are still stable. Moreover, similar to the malignant patients, the visiting nurses should explain the situations to the patients with chronic diseases, that they can choose the place of their own death and specific medical treatment at emergency and can decide the detail for their terminal stage with their family members. Thus, it was considered to be very important that the visiting nurses should frequently confirm these issues with the patients and their family according to their conditions.

Verotoxin-1 induces tissue factor expression in human umbilical vein endothelial cells through activation of NF-kappaB/Rel and AP-1.

This study examined the effect of verotoxin-1 (VT-1), which is released from Escherichia coli O157:H7, on endothelial expression of tissue factor (TF), a cofactor required to initiate blood coagulation. In order to elucidate the molecular basis for development of hemolytic uremic syndrome (HUS) in patients infected with E. coli O157:H7, human umbilical vein endothelial cells (HUVECs) were exposed to purified VT-1. VT-1 increased both TF activity and TF mRNA in HUVECs without loss of cell viability in a time- and dose-dependent manner from 0.1 to 10 ng/ml VT-1. Nuclear proteins extracted from VT-1-stimulated HUVECs bound to the consensus NF-kappaB/Rel and AP-1 binding oligonucleotides in a dose-dependent manner within 2 h after the stimulation in electrophoretic mobility shift assays (EMSA). Nuclear proteins from VT-1-stimulated HUVECs formed two complexes with the NF-kappaB/Rel binding motif in the human TF promoter (TF-kappaB motif). The supershift assays, using antibodies for human p65, p50 or c-Rel, indicated that the lower complex was composed of p65/p50 and the higher complex was a p65 homo- or hetero-dimer with the Rel family, except c-Rel. The human TF promoter contains two AP-1 binding sites, the proximal and distal AP-1 binding sites. The supershift assays indicated that AP-1 containing mainly c-Jun and JunD, positively bound to the proximal AP-1 motif of TF (TF-AP-1). The distal TF-AP-1 motif did not show positive binding with nuclear proteins from VT-1-stimulated HUVECs. Pretreatment of HUVECs with curcumin, an inhibitor of NF-kappaB/Rel activation, synthesis of c-Jun mRNA and binding of activated AP- I with AP-binding oligonucleotide, prevented the VT-1 induced increase in TF mRNA and activity in VT-1-stimulated HUVECs. Curcumin also inhibited NF-kappaB and AP-1 binding to TF-kappaB and proximal TF-AP-1 oligonucleotides, respectively, in a dose-dependent manner. The present work suggests that both the NF-kappaB/Rel and AP-1 activated in endothelial cells by stimulation with VT-1 binds to the TF-kappaB and proximal AP-1 binding sites, respectively, of the TF promoter.