Search for the Majorana Nature of Neutrinos in the Inverted Mass Ordering Region with KamLAND-Zen.

The KamLAND-Zen experiment has provided stringent constraints on the neutrinoless double-beta (0νßß) decay half-life in ^{136}Xe using a xenon-loaded liquid scintillator. We report an improved search using an upgraded detector with almost double the amount of xenon and an ultralow radioactivity container, corresponding to an exposure of 970 kg yr of ^{136}Xe. These new data provide valuable insight into backgrounds, especially from cosmic muon spallation of xenon, and have required the use of novel background rejection techniques. We obtain a lower limit for the 0νßß decay half-life of T_{1/2}^{0ν}>2.3×10^{26} yr at 90% C.L., corresponding to upper limits on the effective Majorana neutrino mass of 36-156 meV using commonly adopted nuclear matrix element calculations.

Validation of the bag-mediated filtration system for environmental surveillance of poliovirus in Nairobi, Kenya.

AIMS: This study compared the bag-mediated filtration system (BMFS) and standard WHO two-phase separation methods for poliovirus (PV) environmental surveillance, examined factors impacting PV detection and monitored Sabin-like (SL) PV type 2 presence with withdrawal of oral polio vaccine type 2 (OPV2) in April 2016. METHODS AND RESULTS: Environmental samples were collected in Nairobi, Kenya (Sept 2015-Feb 2017), concentrated via BMFS and two-phase separation methods, then assayed using the WHO PV isolation algorithm and intratypic differentiation diagnostic screening kit. SL1, SL2 and SL3 were detected at higher rates in BMFS than two-phase samples (P < 0·05). In BMFS samples, SL PV detection did not significantly differ with volume filtered, filtration time or filter shipment time (P > 0·05), while SL3 was detected less frequently with higher shipment temperatures (P = 0·027). SL2 was detected more frequently before OPV2 withdrawal in BMFS and two-phase samples (P < 1 × 10-5 ). CONCLUSIONS: Poliovirus was detected at higher rates with the BMFS, a method that includes a secondary concentration step, than using the standard WHO two-phase method. SL2 disappearance from the environment was commensurate with OPV2 withdrawal. SIGNIFICANCE AND IMPACT OF THE STUDY: The BMFS offers comparable or improved PV detection under the conditions in this study, relative to the two-phase method.

Precision Analysis of the

We present a precision analysis of the ^{136}Xe two-neutrino ßß electron spectrum above 0.8 MeV, based on high-statistics data obtained with the KamLAND-Zen experiment. An improved formalism for the two-neutrino ßß rate allows us to measure the ratio of the leading and subleading 2νßß nuclear matrix elements (NMEs), ξ_{31}^{2ν}=-0.26_{-0.25}^{+0.31}. Theoretical predictions from the nuclear shell model and the majority of the quasiparticle random-phase approximation (QRPA) calculations are consistent with the experimental limit. However, part of the ξ_{31}^{2ν} range allowed by the QRPA is excluded by the present measurement at the 90% confidence level. Our analysis reveals that predicted ξ_{31}^{2ν} values are sensitive to the quenching of NMEs and the competing contributions from low- and high-energy states in the intermediate nucleus. Because these aspects are also at play in neutrinoless ßß decay, ξ_{31}^{2ν} provides new insights toward reliable neutrinoless ßß NMEs.

Publisher's Note: Search for Majorana Neutrinos Near the Inverted Mass Hierarchy Region with KamLAND-Zen [Phys. Rev. Lett. 117, 082503 (2016)].

This corrects the article DOI: 10.1103/PhysRevLett.117.082503.

Search for Majorana Neutrinos Near the Inverted Mass Hierarchy Region with KamLAND-Zen.

We present an improved search for neutrinoless double-beta (0νßß) decay of ^{136}Xe in the KamLAND-Zen experiment. Owing to purification of the xenon-loaded liquid scintillator, we achieved a significant reduction of the ^{110m}Ag contaminant identified in previous searches. Combining the results from the first and second phase, we obtain a lower limit for the 0νßß decay half-life of T_{1/2}^{0ν}>1.07×10^{26} yr at 90% C.L., an almost sixfold improvement over previous limits. Using commonly adopted nuclear matrix element calculations, the corresponding upper limits on the effective Majorana neutrino mass are in the range 61-165 meV. For the most optimistic nuclear matrix elements, this limit reaches the bottom of the quasidegenerate neutrino mass region.

Limit on neutrinoless ßß decay of 136Xe from the first phase of KamLAND-Zen and comparison with the positive claim in 76Ge.

We present results from the first phase of the KamLAND-Zen double-beta decay experiment, corresponding to an exposure of 89.5 kg yr of (136)Xe. We obtain a lower limit for the neutrinoless double-beta decay half-life of T(1/2)(0ν)>1.9×10(25) yr at 90% C.L. The combined results from KamLAND-Zen and EXO-200 give T(1/2)(0ν)>3.4×10(25) yr at 90% C.L., which corresponds to a Majorana neutrino mass limit of <(120-250) meV based on a representative range of available matrix element calculations. Using those calculations, this result excludes the Majorana neutrino mass range expected from the neutrinoless double-beta decay detection claim in (76)Ge, reported by a part of the Heidelberg-Moscow Collaboration, at more than 97.5% C.L.

Experimental investigation of geologically produced antineutrinos with KamLAND.

The detection of electron antineutrinos produced by natural radioactivity in the Earth could yield important geophysical information. The Kamioka liquid scintillator antineutrino detector (KamLAND) has the sensitivity to detect electron antineutrinos produced by the decay of 238U and 232Th within the Earth. Earth composition models suggest that the radiogenic power from these isotope decays is 16 TW, approximately half of the total measured heat dissipation rate from the Earth. Here we present results from a search for geoneutrinos with KamLAND. Assuming a Th/U mass concentration ratio of 3.9, the 90 per cent confidence interval for the total number of geoneutrinos detected is 4.5 to 54.2. This result is consistent with the central value of 19 predicted by geophysical models. Although our present data have limited statistical power, they nevertheless provide by direct means an upper limit (60 TW) for the radiogenic power of U and Th in the Earth, a quantity that is currently poorly constrained.

Evaluation of thrombopoiesis in thrombocytopenic disorders by simultaneous measurement of reticulated platelets of whole blood and serum thrombopoietin concentrations.

To evaluate thrombopoiesis in thrombocytopenic disorders, we simultaneously determined reticulated platelet counts in whole blood by FACScan flow cytometry and serum thrombopoietin (TPO) concentrations by a sensitive sandwich ELISA. The subjects were 40 healthy volunteers and 45 thrombocytopenic patients. In idiopathic thrombocytopenic purpura (ITP), the percentage of reticulated platelets was significantly elevated (5.61 +/- 2.02%: mean +/- SD) relative to normal controls (2.17 +/- 0.90%), but serum TPO concentrations (1.91 +/- 1.27 fmol/l) did not differ significantly from the normal range (1.43 +/- 0.62 fmol/l). The patients with aplastic anemia (AA) had decreased reticulated platelet counts and markedly increased serum TPO concentrations (13.65 +/- 10.64 fmol/l). In thrombocytopenic patients with liver cirrhosis (LC), the absolute number of reticulated platelets (1.65 +/- 1.11 x 10(9)/l) decreased similarly that in AA. However, serum TPO concentrations (1.38 +/- 0.50 fmol/l) did not increase in contrast to AA. Our findings suggested a possible dual mechanism of thrombocytopenia in LC; that is, thrombocytopenia in LC results from the decreased TPO production primarily in the liver adding to an increase in platelet sequestration in the spleen.

Capillary filling analysis by digital subtraction angiography for vertebro-basilar insufficiency.

Vertebro-basilar insufficiency (VBI) is a vague clinical entity including several symptoms such as faintness, dizziness, vertigo. Millikan and Siekert reported a 'syndrome of intermittent insufficiency of basilar arterial system'. But vascular abnormalities responsible for such symptoms are often hardly diagnosed by conventional angiography, because vertebro-basilar artery systems have many kinds of anomalous congenital origins. Conventional angiography gives us arterial informations such as stenosis, occlusion and malformations, but it often fails to reveal capillary perfusions because of its relatively poor density resolution. Digital subtraction angiography (DSA) is considered to have improved density resolution, and it may enable us to detect vascular perfusions more sensitively in the capillary phase. In this study, we evaluated the usefulness of the capillary filling analysis in digital subtraction angiography for diagnosis of VBI.

Lactogenic immunity to transmissible gastroenteritis (TGE) of swine induced by the attenuated Nouzilly strain of TGE virus: passive protection of piglets and detection of serum and milk antibody classes by ELISA.

Piglets of eight sows vaccinated by different routes with the attenuated TGE mutant coronavirus, Nouzilly (N) strain, and piglets from two field seropositive sows were challenged with a virulent TGE strain. On the day of challenge and 10 days after challenge, milk and serum samples from sows were analysed for their level of neutralizing antibodies, total immunoglobulin classes and TGE antibody classes by an ELISA. No direct relationship was seen between the level of protection of the litters and the titres of the different antibody classes on the day of challenge. However, an inverse correlation was seen 10 days after challenge between protection and the level of TGE antibodies.

Adult responses to a survey of soil contact-related behaviors.

Protocols used to assess human exposure to chemicals in soils at contaminated sites often include a dermal pathway. Use of default parameters to assess dermal exposure to soil can easily lead to risk projections that appear to warrant remedial action. However, because those default parameters are typically highly uncertain, risk estimates based upon them inspire little confidence. To better characterize assumptions regarding dermal exposures, a telephone survey instrument was developed to elicit information on behaviors relevant to assessment of dermal contact with soil and dust. Participation in four activities--gardening, other yard work, outdoor team sports, and home construction or repair involving digging--was investigated. Questions were also asked regarding clothing choices and post-activity bathing practices. The survey was administered to two populations of approximately 450 adult respondents each using random digit dialing. The first was a national (U.S.) sample. The second sample was drawn from counties surrounding the Hanford Nuclear Reservation. Seventy-nine percent of the regional respondents and 89% of the national respondents reported participating in at least one of the four targeted activities. Responses of doers regarding clothing choices suggest that median fractions of skin exposed during warm-weather activities typically exceed the 25% often assumed. The Hanford sample differed from the national sample in the fraction residing in single-family homes, the fraction describing their residential surroundings as rural, and in ethnic makeup. The Hanford population displayed greater rates of participation than the national sample in three activities that have an obvious link to residence in a single-family dwelling: home repair involving digging, gardening, and other yard work, but differences were not explained entirely by residence type. The regional population also reported greater frequency of participation in multiple activities. In contrast, clothing choices among doers could not be distinguished between the two groups.

Adult proxy responses to a survey of children's dermal soil contact activities.

Contaminated site cleanup decisions may require estimation of dermal exposures to soil. Telephone surveys represent one means of obtaining relevant activity pattern data. The initial Soil Contact Survey (SCS-I), which primarily gathered information on the activities of adults, was conducted in 1996. Data describing adult behaviors have been previously reported. Results from a second Soil Contact Survey (SCS-II), performed in 1998-1999 and focused on children's activity patterns, are reported here. Telephone surveys were used to query a randomly selected sample of U.S. households. A randomly chosen child, under the age of 18 years, was targeted in each responding household having children. Play activities as well as bathing patterns were investigated to quantify total exposure time, defined as activity time plus delay until washing. Of 680 total survey respondents, 500 (73.5%) reported that their child played outdoors on bare dirt or mixed grass and dirt surfaces. Among these "players," the median reported play frequency was 7 days/week in warm weather and 3 days/week in cold weather. Median play duration was 3 h/day in warm weather and 1 h/day in cold weather. Hand washes were reported to occur a median of 4 times per day in both warm and cold weather months. Bath or shower median frequency was seven times per week in both warm and cold weather. Finally, based on clothing choice data gathered in SCS-I, a median of about 37% of total skin surface is estimated to be exposed during young children's warm weather outdoor play.

Virus distribution and histopathologic changes in organs of chickens inoculated with Newcastle disease virus (avian paramyxovirus-1) isolated from racing pigeons.

The virus distribution and histopathologic changes in organs of 1-week-old chickens inoculated with three representative isolates of Newcastle disease virus isolated from racing pigeons in Japan were examined. All three isolates were recovered from various organs, including brain, for several days, but not from the blood. Results were highly correlated with their high intracerebral pathogenicity indices (ICPI), in spite of their long mean death time of minimum lethal dose (MDT/MLD).

Effects of invert soap with 0.05% sodium hydroxide on infectious bursal disease virus.

The effects of invert soaps with sodium hydroxide on infectious bursal disease virus (IBDV) were studied. Didecyldimethylammonium chloride was most effective, followed by alkylbenzyldimethylammonium chloride and [mono-bis(tri-methylammonium-methylene chloride)]-alkyl (C9-15) toluene. Dilutions without NaOH had little effect on virus titer. Didecyldimethylammonium chloride was further tested for its effects on IBDV by varying temperature, concentration of invert soap, and pH of the dilution. The effect of the invert soap was strong at 40 C, moderate at room temperature, and weak at 4 C. The concentration of invert soap influenced its efficacy at room temperature but not at 4 C. At pH values below 12.9, the invert soap showed decreased efficacy.

Pathogenicity and antigenicity of avian nephritis isolates.

The G-4260, IR-N, M-6, and M-8 strains of avian nephritis virus (ANV) were inoculated orally into 1-day-old specific-pathogen-free chicks of the line PDL-1 for pathological and serological study. Five of 15 chicks inoculated with the G-4260 strain died with visceral urate depositions. One of 15 chicks each inoculated with the M-6 and M-8 strains died with nephrosis and visceral urate deposition, respectively. No chicks inoculated with the IR-N strain died. Mean body weights of ANV-inoculated chicks, except for the IR-N-inoculated chicks, at 14 days postinoculation (PI) were significantly lower than those of control chicks (P less than 0.01). However, interstitial nephritis was observed in all ANV-inoculated birds that were histopathologically examined at 14 days PI. In the serological study, the G-4260 and IR-N strains were classified as the same serotype, and the M-6 and M-8 strains were classified as a different serotype from the G-4260 and IR-N strains. These results indicate that there at least two serotypes of ANV and its strains differ in pathogenicity.

Differences in the induction of urate deposition of specific-pathogen-free chicks inoculated with avian nephritis virus passaged by five different methods.

The G-4260 strain of avian nephritis virus (ANV) was passaged using five different methods as follows: method 1, passage three times in chorioallantoic membrane (CAM) of 11-day-old embryonated eggs (CAM3); method 2, passage twice in CAM and further passage once in yolk sac (YS) of 6-day-old embryonated eggs (CAM2-YS1); method 3, passage 11 times in CAM (CAM11); method 4, passage 10 times in CAM and further passage twice in YS (CAM10-YS2); method 5, passage as in Method 4 and then passage three times in chicken kidney cell culture (CAM10-YS2-CK3). CAM11 and CAM10-YS2 were each inoculated orally into 25 one-day-old specific-pathogen-free (SPF) chicks. Seven chicks in the CAM11-inoculated group and six chicks in the CAM10-YS2-inoculated group died or were killed because they were moribund; all had either nephrosis or urate deposition. CAM3, CAM2-YS1, CAM10-YS2, and CAM10-YS2-CK3 were each inoculated intraperitoneally into 15 one-day-old SPF chicks. No chicks inoculated with CAM3 or CAM2-YS1 died, but wo chicks inoculated with CAM10-YS2 and three inoculated with CAM10-YS2-CK3 died with urate deposition. At 14 postinoculation, plasma urate values of the CAM10-YS2- and CAM10-YS2-CK3-inoculated chicks were significantly higher than those of CAM3- and CAM2-YS1-inoculated chicks and control chicks (P less than 0.01). However, interstitial nephritis was observed in most of the ANV-inoculated birds.

Avian nephritis virus infection of chicks: virology, pathology, and serology.

Avian nephritis virus (ANV), G-4260 strain, was inoculated orally into 1-day-old specific-pathogen-free chicks of the line 15I for virological, pathological, and serological study of the ANV infection of chicks. The virus titer and incidence of appearance of fluorescent antigens in the kidneys were highest at 4 days postinoculation (PI) and decreased gradually. The degeneration of proximal tubules was the principal pathological change in kidneys of chicks at 4 days PI, and interstitial nephritis was the principal pathological change in kidneys of chicks from 6 to 14 days PI. Moreover, gouty nodules were apparent in the kidneys of more than half of the chicks at 10 days PI. The plasma urate value of infected chicks was clearly higher than that of control chicks, reaching a maximum at 10 days PI, then gradually decreasing. The serum antibody was detected from 4 days PI and increased gradually. The chicks affected with visceral urate deposits or urate deposits in the digitated joints showed high plasma urate values (more than 100 mg/dl).

Outbreak of comb necrosis in layer breeder chickens.

Comb necrosis with leg weakness was seen in 41-day-old female layer breeder chickens. This disease occurred in three flocks at a breeder farm, but not in other flocks of growing chickens and broiler breeder hens at the same farm. The disease started in 35-day-old chicks in three flocks. The morbidity of comb necrosis was 10% and that of leg weakness was 3%. Characteristic gross lesions of affected chickens were swelling and necrosis of the whole comb. Histologically, liquefactive necrosis of epidermal epithelial cells with hyperplasia, vesicle formation in the epidermis, congestion, and hemorrhages with fibrinous thrombi of underlying dermis in the comb were noted. In mature comb lesions, the epidermis showed eosinophilic necrosis (scab formation). In the livers, multiple fibrinous thrombi were present in the sinusoids and there was necrosis of hepatic cells. Staphylococcus aureus and Pasturella spp. were isolated from comb lesions. There were no significant lesions causing leg weakness.

Pathologically and serologically different avian nephritis virus isolates implicated in etiology of baby chick nephropathy.

Three virus isolates (WG-3, -4, and -5) from chicks affected by baby chick nephropathy were orally inoculated into 1-day-old specific-pathogen-free chicks of lines PDL-1 and 15I. Additional chicks were orally inoculated with avian nephritis virus (ANV) strain G-4260. Chicks inoculated with isolates WG-3, -4, and -5 died between 2 and 6 days postinoculation (PI), with mortality ranging from 0% to 53.3%. Pathological findings in the dead chicks included nephrosis in chicks inoculated with WG-3, -4, and -5, and nephritis and visceral urate deposition in chicks inoculated with G-4260. The stability of the WG-5 isolate, as well as the size of the particles and the nucleic acid type, were also similar to those of the G-4260 strain. All of the examined chicks inoculated with WG-3, -4, and -5 had interstitial nephritis at 14 days PI. Therefore, the three virus isolates were considered to be ANV. However, there was no serological relationship between the isolates and ANV (G-4260 and M-8 strains).

Serotypes of avian infectious bronchitis virus isolates from field cases in Japan.

Eight etiologic agents isolated from field cases in Japan were identified as isolates of infectious bronchitis virus by agar-gel diffusion, buoyant-density determination on sucrose-density centrifugation, and morphological study by electron microscope of the purified viruses. In studies of the antigenic relationships of the eight isolates and six known infectious bronchitis viruses, antigenic diversity of these viruses was recognized from the degrees of relatedness using a plaque reduction in the "constant-virus decreasing-serum" method.