Laser Excitation of the

LiSrAlF_{6} crystals doped with ^{229}Th are used in a laser-based search for the nuclear isomeric transition. Two spectroscopic features near the nuclear transition energy are observed. The first is a broad excitation feature that produces redshifted fluorescence that decays with a timescale of a few seconds. The second is a narrow, laser-linewidth-limited spectral feature at 148.382 19(4)_{stat}(20)_{sys} nm [2020 407.3(5)_{stat}(30)_{sys} GHz] that decays with a lifetime of 568(13)_{stat}(20)_{sys} s. This feature is assigned to the excitation of the ^{229}Th nuclear isomeric state, whose energy is found to be 8.355 733(2)_{stat}(10)_{sys} eV in ^{229}Th:LiSrAlF_{6}.

Migrant status and risk of compulsory admission at first diagnosis of psychotic disorder: a population-based cohort study in Sweden.

BACKGROUND: Minority ethnic and migrant groups face an elevated risk of compulsory admission for mental illness. There are overlapping cultural, socio-demographic, and structural explanations for this risk that require further investigation. METHODS: By linking Swedish national register data, we established a cohort of persons first diagnosed with a psychotic disorder between 2001 and 2016. We used multilevel mixed-effects logistic modelling to investigate variation in compulsory admission at first diagnosis of psychosis across migrant and Swedish-born groups with individual and neighbourhood-level covariates. RESULTS: Our cohort included 12 000 individuals, with 1298 (10.8%) admitted compulsorily. In an unadjusted model, being a migrant [odds ratio (OR) 1.48; 95% confidence interval (CI) 1.26-1.73] or child of a migrant (OR 1.27; 95% CI 1.10-1.47) increased risk of compulsory admission. However after multivariable modelling, region-of-origin provided a better fit to the data than migrant status; excess risk of compulsory admission was elevated for individuals from sub-Saharan African (OR 1.94; 95% CI 1.51-2.49), Middle Eastern and North African (OR 1.46; 95% CI 1.17-1.81), non-Nordic European (OR 1.27; 95% CI 1.01-1.61), and mixed Swedish-Nordic backgrounds (OR 1.33; 95% CI 1.03-1.72). Risk of compulsory admission was greater in more densely populated neighbourhoods [OR per standard deviation (s.d.) increase in the exposure: 1.12, 95% CI 1.06-1.18], an effect that appeared to be driven by own-region migrant density (OR per s.d. increase in exposure: 1.12; 95% CI 1.02-1.24). CONCLUSIONS: Inequalities in the risk of compulsory admission by migrant status, region-of-origin, urban living and own-region migrant density highlight discernible factors which raise barriers to equitable care and provide potential targets for intervention.

Identification and characterization of bacteriophages specific to the catfish pathogen, Edwardsiella ictaluri.

AIMS: To identify and characterize bacteriophages specific for Edwardsiella ictaluri, the causative agent for enteric septicemia of catfish (ESC). METHODS AND RESULTS: Two bacteriophages were isolated that infect Edw. ictaluri. They both produce clear plaques, have icosahedral heads with a non-rigid tail, and are tentatively classified as Siphoviridae. Phages PhieiDWF and PhieiAU are dsDNA viruses with approximate genome sizes of 40 and 45 kb, respectively. The addition of 500 micromol l(-1) CaCl(2) enhanced phage titres. Both phages have a latent period of 40 min and an estimated burst size of 270. Every Edw. ictaluri strain tested was susceptible to phage infection with variable plaquing efficiencies and with no evidence of lysogeny, with no plaques detected on other bacterial species. CONCLUSIONS: Two unique bacteriophages were isolated that show host-specificity for Edw. ictaluri, have temperature and metal cation-dependent infectivity, and are tentatively placed within the family Siphoviridae. SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first report of bacteriophages specific to Edw. ictaluri, an important fish pathogen affecting farm-raised channel catfish. Initial characterization of these bacteriophages has demonstrated their potential use as biotherapeutic and diagnostic agents associated with ESC.

The effect of signal onset/offset envelope on underwater detection thresholds of a harbor seal (Phoca vitulina).

The effects of signal onset/offset envelope on the underwater hearing thresholds of a harbor seal (Phoca vitulina) were measured. Pure-tone, 540-ms pulses at 2, 4, 8, and 16 kHz were presented as test signals. An ANOVA revealed that there were no significant differences between repeated threshold measures for abrupt onset/offset signal envelopes versus slow onset/offset signal envelopes [F = 4.380, d.f. = (1,18), p > 0.05]. Seal vocalizations which have an abrupt onset/offset may be serving a short-range communicative function by helping the listener determine the direction of a nearby sender.

Descending frequency swept tones have lower thresholds than ascending frequency swept tones for a harbor seal (Phoca vitulina) and human listeners.

Many seal vocalizations consist of frequency swept tones. The signal detection thresholds of a harbor seal (Phoca vitulina) and of human listeners were measured using ascending and descending frequency swept tones at 1/3- and 1-oct bandwidths. The swept tones increased or decreased exponentially and traversed the same frequency range. The sweeps were centered on 2, 4, and 8 kHz for the seal study and 0.5, 1, and 2 kHz for the human listeners. The bandwidth of the sweep did not affect signal detection abilities of either the seal or human listeners. The seal had lower signal detection thresholds (1-5 dB) when presented with the descending frequency swept tones (F = 32.04, df = (1,31), p < 0.000001). Human listeners also had lower detection thresholds for descending frequency swept tones (t = -4.78, df = 52, p < 0.0001). Pinniped ascending frequency swept calls may not function as well as descending frequency sweeps for long-distance communicative signals.

Development of a selection index to improve market value of cultured Atlantic salmon (Salmo salar).

Genetic parameters were estimated on growth and development traits using analyses of variance and covariance of 42 full-sib families from a select line, 39 full-sib families from a control line of the same strain, and 37 full-sib families from another unselected strain. The traits included percent 1+ smolts, percent sexually immature fish after 1 year in seawater (nongrilse), and fork length measured at intervals throughout the production cycle. The number of fish sampled per family was 30 of 300-1500 for all freshwater traits and 15-60, i.e., all individuals present, for all seawater traits. Heritability estimates of freshwater traits had a broad range (0.15-0.61), but estimates were lower for seawater traits (0.06-0.29). There was a general reduction in heritability estimates for traits measured at increasing ages both in freshwater and seawater. These reductions may in part represent declines of maternal and common environmental effects that inflate heritability estimated from full-sib families. The genetic correlations indicated positive associations between freshwater and seawater growth parameters. However, the correlations decreased with increasing intervals between measurements. A selection index was developed using the estimates of the genetic and phenotypic parameters for three economically important traits: percent 1 + smolts, percent nongrilse, and harvest length. The seawater traits, percent nongrilse, and fork length at 17 months (harvest length) were the most important in the index.

Masked threshold changes associated with angular separation of noise and signal sources.

Threshold changes associated with separating a signal source and a masking white noise source from 0 degree to 90 degrees were determined for 0.5, 1 and 8 kHz pure tones and click trains. No changes occurred for the 0.5 and 1 kHz pure tones. Masked thresholds of 8 kHz pure tones and click trains decreased linearly by 9 and 13 dB respectively as angular separation was moved from 0 degree to 90 degrees. Changes in click train stimuli masked thresholds did not change significantly when the ear directed toward the masking source was occluded (11 dB drop at 90 degrees). The absence of changes at low frequencies and the similarity in magnitude of the changes in signals containing high frequency components with the responses to the monaural click trains, suggests that the threshold changes can be attributed to a head shadow effect. The casting of a sound shadow effectively lowers the noise level on the shielded side. These findings question the importance of cross-correlation techniques when detecting signals in noise.

Localization of pure tones and click trains by untrained humans.

Minimum audible angles (m.a.a.s) of untrained subjects were measured in a room using pure tone (0.5 to 8 kHz) and click train (noise) stimuli (two alternative, forced-choice, constant stimulus with feedback and head movements permitted, horizontal plane, 0 degree azimuth). The m.a.a.s and standard deviations (SD) were 3.0 degrees +/- 5.2 degrees for click trains and 10.9 degrees +/- 21.0 degrees for pure tones. The m.a.a.s did not vary significantly with frequency. The m.a.a.s and their SDs matched values reported from localization error studies. Narrowing the testing range from 32 degrees to 8 degrees resulted in random responses to the pure tones, though the click trains were readily localized. One subject presented with 2500 trials using an 8 kHz pure tone (with feedback, 16 degrees range) increased her responses from random to 88% correct during the testing. The click train m.a.a.s probably reflect the typical noise localizational abilities of the general population. For pure-tone m.a.a.s, experience/training may result in improved accuracy not applicable to the general public. The presence of a well defined time clue and a broad bandwidth sound results in significantly lower m.a.a.s than were obtained using pure tones which presumably present only interaural phase or intensity clues.