Search for Dark Photon Dark Matter in the Mass Range 74-110 µeV with a Cryogenic Millimeter-Wave Receiver.

We search for the dark photon dark matter (DPDM) using a cryogenic millimeter-wave receiver. DPDM has a kinetic coupling with electromagnetic fields with a coupling constant of χ and is converted into ordinary photons at the surface of a metal plate. We search for signal of this conversion in the frequency range 18-26.5 GHz, which corresponds to the mass range 74-110 µeV/c^{2}. We observed no significant signal excess, allowing us to set an upper bound of χ<(0.3-2.0)×10^{-10} at 95% confidence level. This is the most stringent constraint to date and tighter than cosmological constraints. Improvements from previous studies are obtained by employing a cryogenic optical path and a fast spectrometer.

Effect of Whey-Derived Lactopeptide ß-Lactolin on Memory in Healthy Adults: An Integrated Analysis of Data from Randomized Controlled Trials.

CONTEXT: Epidemiological studies have shown that consumption of dairy products reduces the risk of dementia and cognitive decline in older individuals. Tryptophan-tyrosine-related ß-lactopeptides and their representative ß-lactolin of glycine-threonine-tryptophan-tyrosine tetra-peptide have been identified as agents in dairy products, which improve cognitive function as well as memory function via the activation of the dopaminergic system in a mouse model of amnesia. Previous clinical trials have shown that supplementation with ß-lactolin improves memory retrieval in healthy older adults. Specifically, ß-lactolin improved the scores in some neuropsychological tests. However, the effects of ß-lactolin on memory function have not been clarified. OBJECTIVES: The aim of this study was to evaluate the effect of ß-lactolin on memory function using statistical methods. DATA SOURCES: We searched the Web of Science, Cochrane Library, and JDream III until November 2021 to identify relevant randomized controlled trials for integrated analysis. DATA SYNTHESIS: Three randomized controlled trials evaluating the effect of ß-lactolin on memory in healthy adults were selected for the integrated analysis. The results showed that the score of cued recall among the neuropsychological tests in the ß-lactolin group was significantly higher than that in the placebo group (g=0.33; 95% CI: 0.10, 0.55). In addition, the total memory score was higher but this difference was not significant (g=0.17; 95% CI: -0.09, 0.43). CONCLUSIONS: Taken together, these results suggest that supplementation with ß-lactolin improves cued recall in healthy older adults.

Material survey for a millimeter-wave absorber using a 3D-printed mold.

Radio absorptive materials (RAMs) are key elements for receivers in the millimeter-wave range. We previously established a method for production of RAM by using a 3D-printed mold. An advantage of this method is a wide range of choices for absorptive materials to be used. To take advantage of this flexibility, we added a range of absorptive materials to a base epoxy resin, STYCAST-2850FT, and examined the optical performance of the resultant RAM across a wide frequency range under cryogenic conditions. We found that adding a particular type of carbon fiber produced the best performance with a reflectance at 77 K estimated as 0.01%-3% over a frequency range of 20-300 GHz.

Internal Delensing of Cosmic Microwave Background Polarization B-Modes with the POLARBEAR Experiment.

Using only cosmic microwave background polarization data from the polarbear experiment, we measure B-mode polarization delensing on subdegree scales at more than 5σ significance. We achieve a 14% B-mode power variance reduction, the highest to date for internal delensing, and improve this result to 22% by applying for the first time an iterative maximum a posteriori delensing method. Our analysis demonstrates the capability of internal delensing as a means of improving constraints on inflationary models, paving the way for the optimal analysis of next-generation primordial B-mode experiments.

Production method of millimeter-wave absorber with 3D-printed mold.

We established a production method of a millimeter-wave absorber by using a 3D-printed mold. The mold has a periodic pyramid shape, and an absorptive material is filled into the mold. This shape reduces the surface reflection. The 3D-printed mold is made from a transparent material in the millimeter-wave range. Therefore, unmolding is not necessary. A significant benefit of this production method is easy prototyping with various shapes and various absorptive materials. We produced a test model and used a two-component epoxy encapsulant as the absorptive material. The test model achieved a low reflectance: ∼1% at 100 GHz. The absorber is sometimes maintained at a low temperature condition for cases in which superconducting detectors are used. Therefore, cryogenic performance is required in terms of a mechanical strength for the thermal cycles, an adhesive strength, and a sufficient thermal conductivity. We confirmed the test-model strength by immersing the model into a liquid-nitrogen bath.

The POLARBEAR Fourier transform spectrometer calibrator and spectroscopic characterization of the POLARBEAR instrument.

We describe the Fourier Transform Spectrometer (FTS) used for in-field testing of the POLARBEAR receiver, an experiment located in the Atacama Desert of Chile which measures the cosmic microwave background (CMB) polarization. The POLARBEAR-FTS (PB-FTS) is a Martin-Puplett interferometer designed to couple to the Huan Tran Telescope (HTT) on which the POLARBEAR receiver is installed. The PB-FTS measured the spectral response of the POLARBEAR receiver with signal-to-noise ratio >20 for ∼69% of the focal plane detectors due to three features: a high throughput of 15.1 sr cm2, optimized optical coupling to the POLARBEAR optics using a custom designed output parabolic mirror, and a continuously modulated output polarizer. The PB-FTS parabolic mirror is designed to mimic the shape of the 2.5 m-diameter HTT primary reflector, which allows for optimum optical coupling to the POLARBEAR receiver, reducing aberrations and systematics. One polarizing grid is placed at the output of the PB-FTS and modulated via continuous rotation. This modulation allows for decomposition of the signal into different harmonics that can be used to probe potentially pernicious sources of systematic error in a polarization-sensitive instrument. The high throughput and continuous output polarizer modulation features are unique compared to other FTS calibrators used in the CMB field. In-field characterization of the POLARBEAR receiver was accomplished using the PB-FTS in April 2014. We discuss the design, construction, and operation of the PB-FTS and present the spectral characterization of the POLARBEAR receiver. We introduce future applications for the PB-FTS in the next-generation CMB experiment, the Simons Array.

Note: Sub-Kelvin refrigeration with dry-coolers on a rotating system.

We developed a cryogenic system on a rotating table that achieves sub-Kelvin conditions. The cryogenic system consists of a helium sorption cooler and a pulse tube cooler in a cryostat mounted on a rotating table. Two rotary-joint connectors for electricity and helium gas circulation enable the coolers to be operated and maintained with ease. We performed cool-down tests under a condition of continuous rotation at 20 rpm. We obtained a temperature of 0.23 K with a holding time of more than 24 h, thus complying with catalog specifications. We monitored the system's performance for four weeks; two weeks with and without rotation. A few-percent difference in conditions was observed between these two states. Most applications can tolerate such a slight difference. The technology developed is useful for various scientific applications requiring sub-Kelvin conditions on rotating platforms.

Radio-transparent multi-layer insulation for radiowave receivers.

In the field of radiowave detection, enlarging the receiver aperture to enhance the amount of light detected is essential for greater scientific achievements. One challenge in using radio transmittable apertures is keeping the detectors cool. This is because transparency to thermal radiation above the radio frequency range increases the thermal load. In shielding from thermal radiation, a general strategy is to install thermal filters in the light path between aperture and detectors. However, there is difficulty in fabricating metal mesh filters of large diameters. It is also difficult to maintain large diameter absorptive-type filters in cold because of their limited thermal conductance. A technology that maintains cold conditions while allowing larger apertures has been long-awaited. We propose radio-transparent multi-layer insulation (RT-MLI) composed from a set of stacked insulating layers. The insulator is transparent to radio frequencies, but not transparent to infrared radiation. The basic idea for cooling is similar to conventional multi-layer insulation. It leads to a reduction in thermal radiation while maintaining a uniform surface temperature. The advantage of this technique over other filter types is that no thermal links are required. As insulator material, we used foamed polystyrene; its low index of refraction makes an anti-reflection coating unnecessary. We measured the basic performance of RT-MLI to confirm that thermal loads are lowered with more layers. We also confirmed that our RT-MLI has high transmittance to radiowaves, but blocks infrared radiation. For example, RT-MLI with 12 layers has a transmittance greater than 95% (lower than 1%) below 200 GHz (above 4 THz). We demonstrated its effects in a system with absorptive-type filters, where aperture diameters were 200 mm. Low temperatures were successfully maintained for the filters. We conclude that this technology significantly enhances the cooling of radiowave receivers, and is particularly suitable for large-aperture systems. This technology is expected to be applicable to various fields, including radio astronomy, geo-environmental assessment, and radar systems.

Cryogenic cooling with cryocooler on a rotating system.

We developed a system that continuously maintains a cryocooler for long periods on a rotating table. A cryostat that holds the cryocooler is set on the table. A compressor is located on the ground and supplies high-purity (>99.999%) and high-pressure (1.7 MPa) helium gas and electricity to the cryocooler. The operation of the cryocooler and other instruments requires the development of interface components between the ground and rotating table. A combination of access holes at the center of the table and two rotary joints allows simultaneous circulation of electricity and helium gas. The developed system provides two innovative functions under the rotating condition, cooling from room temperature and the maintenance of a cold condition for long periods. We have confirmed these abilities as well as temperature stability under a condition of continuous rotation at 20 rpm. The developed system can be applied in various fields, e.g., in tests of Lorentz invariance, searches for axion, radio astronomy, and cosmology, and application of radar systems. In particular, there is a plan to use this system for a radio telescope observing cosmic microwave background radiation.

Note: innovative demodulation scheme for coherent detectors in cosmic microwave background experiments.

We propose an innovative demodulation scheme for coherent detectors used in cosmic microwave background polarization experiments. Removal of non-white noise, e.g., narrow-band noise, in detectors is one of the key requirements for the experiments. A combination of modulation and demodulation is used to extract polarization signals as well as to suppress such noise. Traditional demodulation, which is based on the two-point numerical differentiation, works as a first-order high pass filter for the noise. The proposed demodulation is based on the three-point numerical differentiation. It works as a second-order high pass filter. By using a real detector, we confirmed significant improvements of suppression power for the narrow-band noise. We also found improvement of the noise floor.

Calibration system with cryogenically-cooled loads for cosmic microwave background polarization detectors.

We present a novel system to calibrate millimeter-wave polarimeters for cosmic microwave background (CMB) polarization measurements. This technique is an extension of the conventional metal mirror rotation approach, however, it employs cryogenically-cooled blackbody absorbers. The primary advantage of this system is that it can generate a slightly polarized signal (∼100 mK) in the laboratory; this is at a similar level to that measured by ground-based CMB polarization experiments observing a ∼10 K sky. It is important to reproduce the observing condition in the laboratory for reliable characterization of polarimeters before deployment. In this paper, we present the design and principle of the system and demonstrate its use with a coherent-type polarimeter used for an actual CMB polarization experiment. This technique can also be applied to incoherent-type polarimeters and it is very promising for the next-generation CMB polarization experiments.

A psychopharmacological treatment algorithm for generalised anxiety disorder (GAD).

Generalised anxiety disorder (GAD) is defined as excessive and uncontrollable worry and anxiety about everyday life situations. It is a chronic disorder, and is associated with substantial somatisation, high rates of comorbid depression and other anxiety disorders, and significant disability. The evidence base for pharmacotherapy and psychotherapy has continued to grow, and a wide range of drug choices for GAD now exists. Current guidelines for GAD generally restrict themselves to presentation of the evidence for various treatments, which, as a result, generally do not offer detailed discussion or recommendation of strategies beyond the first level of treatment, or take into account the individual circumstances of the patient. Thus, there is a lack of algorithm-based treatment guidelines for GAD. Our aim is, therefore, to present an algorithm for the psychopharmacologic management of GAD, intended for all clinicians who treat patients with GAD, where issues of pharmacotherapy are under consideration. We also hope that these GAD algorithms and other guidelines can help to identify high-priority areas that need further study. In this algorithm, we provide a sequenced approach to the pharmacotherapy of GAD, taking into account salient symptomatology and comorbidity, levels of evidence and extent of response. Special issues, including comorbidity, insomnia, suicidality, substance abuse, treatment adherence, pregnancy and lactation, cross-cultural issues, use of medication in the elderly, psychosocial treatment and dosing issues are also addressed.

Search for invisible decay of the Upsilon(1S).

We report results of a search for the invisible decay of the Upsilon(1S) via the Upsilon(3S)-->pi+ pi- Upsilon(1S) transition using a data sample of 2.9 fb-1 at the Upsilon(3S) resonance. The data were collected with the Belle detector at the KEKB asymmetric-energy e+ e- collider. No signal is found, and an upper limit for the branching fraction at the 90% confidence level is determined to be B(Upsilon(1S)-->invisible)<2.5 x 10(-3).

Observation of time-dependent CP violation in B0 --> eta'K0 decays and improved measurements of CP asymmetries in B0 --> phiK0, KS0KS0KS0 and B0 --> J/psiK0 decays.

We present improved measurements of CP-violation parameters in B(0) --> phiK(0), eta(')K(0), KS(0)KS(0)KS(0) decays based on a sample of 535 x 10(6) BB pairs collected at the Upsilon(4S) resonance with the Belle detector at the KEKB energy-asymmetric e(+)e(-) collider. We obtain sin2phi1(eff)=+0.64+/-0.10(stat)+/-0.04(syst) for B(0) --> eta(')K(0), +0.50+/-0.21(stat)+/-0.06(syst) for B(0) --> phiK(0), and +0.30+/-0.32(stat)+/-0.08(syst) for B(0) --> KS(0)KS(0)KS(0) decays. We have observed CP violation in the B(0) --> eta(')K(0) decay with a significance of 5.6 standard deviations. We also perform an improved measurement of CP asymmetries in B(0) --> J/psiK(0) decays and obtain sin2phi1=+0.642+/-0.031(stat)+/-0.017(syst).

Search for the CP-violating decays Upsilon(4S)-->B0B0-->J/psiKS0+J/psi(etac)KS0.

We report the first search for CP-violating decays of the Upsilon(4S) using a data sample that contains 535 x 10(6) Upsilon(4S) mesons with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider. A partial reconstruction technique is employed to enhance the signal sensitivity. No significant signals were observed. We obtain an upper limit of 4 x 10(-7) at the 90% confidence level for the branching fractions of the CP violating modes, Upsilon(4S)-->B(0)B(0)-->J/psiK(S)(0)+J/psi(eta(c))K(S)(0). Extrapolating the result, we find that an observation with 5sigma significance is expected with a 30 ab(-1) data sample, which is within the reach of a future super B factory.

Sensory nerve-dominant nerve degeneration and remodeling in the mutant mice lacking complex gangliosides.

Gangliosides, sialic acid-containing glycosphingo-lipids, are enriched in the mammalian nervous system. Since mutant mice with disrupted beta1,4-N-acetylgalactosaminyl-transferase (GM2/GD2 synthase) were generated, there have been several studies on the pathology of the mutant mice, i.e. mild functional disorders and Wallerian degeneration in the peripheral nervous system. To further analyze the chronological alteration in the mutant mice, we examined the peripheral and CNS mainly with morphological approaches, such as electron microscopy and immunohistochemistry. Accordingly with the sensory dysfunction, neural degeneration, glial proliferation and synaptic remodeling in the dorsal horn of the spinal cord were found in adult mice. Thick astrocytic processes with densely packed glial filaments were extended among the neuropils and around blood vessels. Morphological changes in the synaptic vesicles and modes of synaptic contacts with central terminals were detected, suggesting synaptic remodeling following the degeneration. These results suggest that complex gangliosides are essential in the maintenance of integrity in architecture and function of the nervous system, lack of which results in neural degeneration in a sensory nerve-dominant manner.

Measurement of neutrino oscillation with KamLAND: evidence of spectral distortion.

We present results of a study of neutrino oscillation based on a 766 ton/year exposure of KamLAND to reactor antineutrinos. We observe 258 nu (e) candidate events with energies above 3.4 MeV compared to 365.2+/-23.7 events expected in the absence of neutrino oscillation. Accounting for 17.8+/-7.3 expected background events, the statistical significance for reactor nu (e) disappearance is 99.998%. The observed energy spectrum disagrees with the expected spectral shape in the absence of neutrino oscillation at 99.6% significance and prefers the distortion expected from nu (e) oscillation effects. A two-neutrino oscillation analysis of the KamLAND data gives Deltam(2)=7.9(+0.6)(-0.5)x10(-5) eV(2). A global analysis of data from KamLAND and solar-neutrino experiments yields Deltam(2)=7.9(+0.6)(-0.5)x10(-5) eV(2) and tan((2)theta=0.40(+0.10)(-0.07), the most precise determination to date.

Observation of the radiative decay D0-->phigamma.

We report the observation of the decay D0-->phigamma with a statistical significance of 5.4sigma in 78.1 fb(-1) of data collected by the Belle experiment at the KEKB e+e- collider. This is the first observation of a flavor-changing radiative decay of a charmed meson. The Cabibbo- and color-suppressed decays D0-->phipi(0), phieta are also observed for the first time. We measure branching fractions B(D0-->phigamma)=[2.60(+0.70)(-0.61)(stat)+0.15-0.17(syst)] x 10(-5), B(D0-->phipi(0))=[8.01+/-0.26(stat)+/-0.47(syst)] x 10(-4), and B(D0-->phieta)=[1.48+/-0.47(stat)+/-0.09(syst)] x 10(-4).

High sensitivity search for nu;e's from the sun and other sources at KamLAND.

Data corresponding to a KamLAND detector exposure of 0.28 kton yr has been used to search for nu;(e)'s in the energy range 8.3

First results from KamLAND: evidence for reactor antineutrino disappearance.

KamLAND has measured the flux of nu;(e)'s from distant nuclear reactors. We find fewer nu;(e) events than expected from standard assumptions about nu;(e) propagation at the 99.95% C.L. In a 162 ton.yr exposure the ratio of the observed inverse beta-decay events to the expected number without nu;(e) disappearance is 0.611+/-0.085(stat)+/-0.041(syst) for nu;(e) energies >3.4 MeV. In the context of two-flavor neutrino oscillations with CPT invariance, all solutions to the solar neutrino problem except for the "large mixing angle" region are excluded.