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The development of a transportable microwave frequency standard based on the ground-state transition of 171Yb+ at ∼12.6 GHz requires a compact laser system for cooling the ions, clearing out of long-lived states and also for photoionisation. In this paper, we describe the development of a suitable compact laser system based on a 6U height rack-mounted arrangement with overall dimensions 260 × 194 × 335 mm. Laser outputs at 369 nm (for cooling), 399 nm (photoionisation), 935 nm (repumping), and 760 nm (state clearout) are combined in a fiber arrangement for delivery to our linear ion trap and we demonstrate this system by cooling of 171Yb+ ions. Additionally, we demonstrate that the lasers at 935 nm and 760 nm are close in frequency to water vapor and oxygen absorption lines, respectively; specifically, at 760 nm, we show that one 171Yb+ transition is within the pressure broadened profile of an oxygen line. These molecular transitions form convenient wavelength references for the stabilization of lasers for a 171Yb+ frequency standard. [ABSTRACT FROM AUTHOR]

We report the design and characterization of an optical shutter based on a piezoelectric cantilever. Compared to conventional electro-magnetic shutters, the device has intrinsically low power and is acoustically quiet. The cantilever position is controlled by a high-voltage op-amp circuit for easy tuning of the range of travel, and mechanical slew rate, which enables a factor of 30 reduction in mechanical noise compared to a rapidly switched device. We achieve shuttering rise and fall times of 11 μs, corresponding to mechanical slew rates of 1.3 ms-1, with a timing jitter of less than 1 μs. When used to create optical pulses, we achieve minimum pulse durations of 250 μs. The reliability of the shutter was investigated by operating continuously for one week at 10 Hz switching rate. After this period, neither the shutter delay or actuation speed had changed by a measurable amount. [ABSTRACT FROM AUTHOR]

Purpose: To elucidate the heritability of peak density and spatial width of macular pigment (MP) using a Classical Twin Study.Methods: Fundus autofluorescence images were obtained at 488 nm from 86 subjects or 43 twin pairs (21 monozygotic (MZ) and 22 dizygotic (DZ)) (27 male, 59 female) aged from 55 to 76 years (mean 62.2 ± 5.3 years). The relative topographic distribution of MP was measured using a grey scale of intensity (0-255 units) in a 7° eccentricity around the fovea. Relative peak MP density (rPMPD) and relative spatial distribution of MP (rSDMP) were used as the main outcome measure in the statistical analysis.Results: A significantly higher correlation was found within MZ pairs as compared with that within DZ pairs for rPMPD, (r=0.99, 95% confidence interval (95% CI) 0.93 to 1.00) and 0.22, 95% CI -0.34 to 0.71), respectively, suggesting strong heritability of this trait. When rSDMP was compared, there was no significant difference between the correlations within MZ pairs (r=0.48, 95% CI -0.02 to 0.83) and DZ pairs (r=0.63, 95% CI 0.32 to 0.83), thus rSDMP is unlikely to have a considerable heritable component. In addition, there was no difference between any MP parameter when normal maculae were compared with early age-related macular degeneration (AMD) (rPMPD 0.36 vs 0.34, t=1.18 P=0.243, rSDMP 1.75 vs 1.75, t=0.028 P=0.977).Conclusions: rPMPD is a strongly heritable trait whereas rSDMP has minimal genetic influence and a greater influence by environmental factors. The presence of macular changes associated with early AMD did not appear to influence any of these pigment parameters. [ABSTRACT FROM AUTHOR]

PurposeTo elucidate the heritability of peak density and spatial width of macular pigment (MP) using a Classical Twin Study.MethodsFundus autofluorescence images were obtained at 488 nm from 86 subjects or 43 twin pairs (21 monozygotic (MZ) and 22 dizygotic (DZ)) (27 male, 59 female) aged from 55 to 76 years (mean 62.2±5.3 years). The relative topographic distribution of MP was measured using a grey scale of intensity (0-255 units) in a 7° eccentricity around the fovea. Relative peak MP density (rPMPD) and relative spatial distribution of MP (rSDMP) were used as the main outcome measure in the statistical analysis.ResultsA significantly higher correlation was found within MZ pairs as compared with that within DZ pairs for rPMPD, (r=0.99, 95% confidence interval (95% CI) 0.93 to 1.00) and 0.22, 95% CI −0.34 to 0.71), respectively, suggesting strong heritability of this trait. When rSDMP was compared, there was no significant difference between the correlations within MZ pairs (r=0.48, 95% CI −0.02 to 0.83) and DZ pairs (r=0.63, 95% CI 0.32 to 0.83), thus rSDMP is unlikely to have a considerable heritable component. In addition, there was no difference between any MP parameter when normal maculae were compared with early age-related macular degeneration (AMD) (rPMPD 0.36 vs 0.34, t=1.18 P=0.243, rSDMP 1.75 vs 1.75, t=0.028 P=0.977).ConclusionsrPMPD is a strongly heritable trait whereas rSDMP has minimal genetic influence and a greater influence by environmental factors. The presence of macular changes associated with early AMD did not appear to influence any of these pigment parameters. [ABSTRACT FROM AUTHOR]

An absolute frequency measurement has been made of the 2S1/2-2F7/2 electric octupole transition in a single ion of 171Yb+. The implementation of a diode-based probe laser stabilized to this highly forbidden transition has resulted in an improvement of more than one order of magnitude upon the lowest published uncertainty. After correcting for systematic shifts, the frequency was determined to be 642 121 496 772 646.22 (67) Hz. This corresponds to a fractional uncertainty of 1.0×10-15. [ABSTRACT FROM AUTHOR]

The initial incursion of pandemic (H1N1) 2009 influenza A virus (pH1N1) into a European pig population is reported. Diagnosis of swine influenza caused by pandemic virus was made during September 2009 following routine submission of samples for differential diagnosis of causative agents of respiratory disease, including influenza A virus. All four pigs (aged six weeks) submitted for investigation from a pig herd of approximately 5000 animals in Northern Ireland, experiencing acute-onset respiratory signs in finishing and growing pigs, were positive by immunofluorescence for influenza A. Follow-up analysis of lung tissue homogenates by real-time RT-PCR confirmed the presence of pH1N1. The virus was subsequently detected on two other premises in Northern Ireland; on one premises, detection followed the pre-export health certification testing of samples from pigs presumed to be subclinically infected as no clinical signs were apparent. None of the premises was linked to another epidemiologically. Sequencing of the haemagglutinin and neuraminidase genes revealed high nucleotide identity (>99.4 per cent) with other pH1N1s isolated from human beings. Genotypic analyses revealed all gene segments to be most closely related to those of contemporary pH1N1 viruses in human beings. It is concluded that all three outbreaks occurred independently, potentially as a result of transmission of the virus from human beings to pigs. [ABSTRACT FROM AUTHOR]

That the media is negative towards Islam, Muslims, the Middle East and Arabs was the view of the vast majority of 1,515 adolescents surveyed in York in 2004. When measured against the Attitudes towards Muslim Proximity Index (AMPI) the data showed a significant association between the media as their primary source of information and negative attitudes towards Muslims. But when measured against their level of knowledge of Islam, Muslims, the Middle East and Arabs the media had only a very slight association, and none when measured against their responses to specific questions on their attitudes in this area. Indeed, when measured against their attitudes towards the British National Party (BNP), an organization known for its anti-Muslim stance, the data showed a relationship between watching the news on television and strong disagreement with BNP views. The conclusion is that what negative attitudes the adolescents had were not a direct result of media influence. [ABSTRACT FROM AUTHOR]

Purpose: The genes in myopia twin study were established to assess the relative genetic contribution of spherical equivalent using a classical twin model. This manuscript will provide a detailed outline of the methodological design, twin recruitment, and the prevalence of myopia in the genes in myopia twin study. Methods: All Victorian-based twins registered with the Australian Twin Registry aged 18 years or older were invited to participate genes in myopia twin study. Each subject underwent a general questionnaire, comprehensive eye examination, and a blood sample was collected. Myopia was defined as worse than or equal to -0.50 diopters sphere (in at least one eye). Results: A total of 627 twin pairs out of 4,158 twin pairs consented to participate in the genes in myopia twin study. A total of 345 monozygotic and 267 dizygotic twin pairs aged between 18 and 86 years were examined. The response rate for monozygotic twins (19.8%) was almost double that of dizygotic twins (11.7%). The overall prevalence of myopia was 29.7% for all twins. Conclusions: The genes in myopia twin study is the first Australian-based twin study to assess refraction in an adult twin population and the largest of its kind in the world. The comprehensive testing protocol used in the in the genes in myopia twin study has provided an extensive twin database for genetic analysis. Participation rate was found to vary according to zygosity, gender, and age. [ABSTRACT FROM AUTHOR]

Two experimental underwater acoustic projectors, a tonpilz array, and a cylindrical line array, were built with single crystal, lead magnesium niobate/lead titanate, a piezoelectric transduction material possessing a large electromechanical coupling factor (k33=0.9). The mechanical quality factor, Qm, and the effective coupling factor, keff, determine the frequency band over which high power can be transmitted; keff cannot be greater than the piezoelectric material value, and so a high material coupling factor is a requisite for broadband operation. Stansfield’s bandwidth criteria are used to calculate the optimum Qm value, Qopt∼1.2 (1-keff2)1/2/keff. The results for the tonpilz projector exhibited keff=0.730, Qm=1.17 (very near optimal), and a fractional bandwidth of 0.93. For the cylindrical transducer array, keff=0.867, Qm=0.91 (larger than the optimum value, 0.7), and the bandwidth was 1.16. Although the measured bandwidths were less than optimal, they were accurately predicted by the theory, despite the highly simplified nature of the Van Dyke equivalent circuit, on which the theory is based. [ABSTRACT FROM AUTHOR]

AIMS:Age-related macular degeneration (AMD) is considered a complex genetic disease, although the genetic influences are not yet fully understood. Genetic analysis is hampered by the late onset of disease and the difficulty in obtaining multigenerational families. To investigate this problem further we studied our population of early onset drusen cases. The Arg345Trp mutation on exon 10 of the EGF-containing fibulin-like extracellular matrix protein 1 (EFEMP1) gene causes two clinical phenotypes of early onset drusen (Doyne honeycomb retinal dystrophy and Malattia Leventinese), yet does not appear to be involved in other early onset drusen phenotypes or typical AMD. We wished to ascertain the involvement of the EFEMP1 gene in our population of sporadic and familial subjects presenting with early onset drusen and their affected relatives. METHODS:Individuals presenting with drusen/end-stage maculopathy at 60 years or under were identified from retinal clinics in Melbourne. All available first- and second-degree relatives were also examined. In all, 116 ethnically matched controls were collected from the same community for comparison. RESULTS:Single stranded conformational polymorphism (SSCP) analysis and subsequent sequencing revealed four previously described and three novel sequence variations. Most occurred at similar frequencies in the case and control populations and were not thought to be disease associated. CONCLUSION:The term early onset drusen encompasses a wide range of phenotypes and our findings indicate that it is likely that more than one gene is involved in its causation. It is essential that these clinical phenotypes are well described and categorised to allow greater possibility of success in the search for other disease genes.Eye (2005) 19, 11-15. doi:10.1038/sj.eye.6701435 Published online 25 June 2004 [ABSTRACT FROM AUTHOR]

Focuses on ethical issues surrounding the application of reproductive technology. Role of the government in the administration of reproductive technology; Principles of equality and justice in access to donor insemination; Moral status of the zygote and embryo in clinical research; Social and ethical issues in selecting sex of offspring.

Then is little available literature on survival data in the form of lifetables for babies born with anencephaly. These data would be valuable in advising parents, who often request very specific information on the length of time their child might survive. Survival is examined for a cohort of anencephalic infants in a well-defined population. Sex-specific survival tables are given, since these are the most practical to use for counselling purposes. These data show that over 40 percent of liveborn anencephalic infants (51% males; 34% females) survive longer than 24 hours, and of these, 5 percent are still alive on the seventh day. Data also are presented on the types of malformations observed in addition to anencephaly. [ABSTRACT FROM AUTHOR]

In 1951 in studies in New Brunswick, increases in the height and width of potato plants were greatest during the fifth week after emergence. The average daily increase at this time was approximately 7/10 inches in height and 8/10 in width. The thickness of the main stalk increased most rapidly from July 28 to August 3, or during the latter part of the fourth week after emergence. After this the rate of increase dropped rapidly, levelling off about August 13. The products of increases in height and in width show that the rate of development of the potato was greatest during the fourth or fifth week after plant emergence. The products of photographic measurements of height and width of plants show that, in 1950 and 1951, greatest growth occurred during the fifth and fourth weeks, respectively, after plant emergence. [ABSTRACT FROM AUTHOR]

A description of the "Home Economics" curriculum taught as an option in secondary schools in Northern Ireland is presented.

We report on the development of a trapped-ion, microwave frequency standard based on the 12.6 GHz hyperfine transition in laser-cooled ytterbium-171 ions. The entire system fits into a 6U 19-in. rack unit (51 × 49 × 28 cm) and comprises laser, electronics, and physics package subsystems. As a first step towards a full evaluation of the system capability, we have measured the frequency instability of our system which is 3.6 × 10 - 12 / √ τ for averaging times between 30 and 1500 s . [ABSTRACT FROM AUTHOR]

The 1 S( F=1)−2 S( F=1) energy interval in muonium has been investigated by Doppler-free two-photon laser spectroscopy. The transition was observed by uniquely identifying and counting the muons released after the photoionization of the 2 S state by the same laser field. The measured transition frequency of 2455 528016(58)(43) MHz is in good agreement with QED calculations. The experiment can be interpreted as a test of the Lamb shift contributions at the 1% level. The method is also well suited for a precise determination of the mass of the positive muon in a muoniumhydrogen isotope shift measurement. [ABSTRACT FROM AUTHOR]

We have measured isotope shifts in λ326.1 nm of CdI using a pressure-scanned interferometer. The results are, in GHz: 116-106, −2.222 (30); 113-108, −1.052(10); 111-110, −0.049 (12); 111-106, −1.048 (10). Results for stable isotopes in λ326.1 nm are needed in the interpretation of existing measurements on radioactive cadmium isotopes. The new data are more precise than early atomic beam measurements but are reasonably consistent with them. [ABSTRACT FROM AUTHOR]

An electron-beam ion trap (EBIT) has just been completed in the Clarendon Laboratory, Oxford. The design is similar to the devices installed at the Lawrence Livermore National Laboratory. It is intended that the Oxford EBIT will be used for x-ray and UV spectroscopy of hydrogenic and helium-like ions, laser resonance spectroscopy of hydrogenic ions and measurements of dielectronic recombination cross sections, in order to test current understanding of simple highly charged ions. [ABSTRACT FROM AUTHOR]

The field isotope shift constant C for a uniform nuclear charge distribution has been re-evaluated for s-electrons for elements with 10≦ Z≦ 95. A table is given which permits C to be found for any isotope pair. [ABSTRACT FROM AUTHOR]

Clindamycin phosphate is an antibiotic which is effective against both Staphylococcus aureus and the anaerobic organisms. In thirteen patients, its concentration following joint replacement was measured by the agar diffusion method. In bone, the concentration was (mean +/- s.e. mean) 5.01 microgram/ml +/- 1.16, N=10; in capsule, 3.29 microgram/ml +/- 0.71, N=12; measured between 1.75 and 3.75 hr after intramuscular and intravenous injections, and in drainage fluid it amounted to 4.61 microgram/ml +/- 0.38, N=11 in 48 hr. Two patients developed diarrhoea which settled within a short period. [ABSTRACT FROM PUBLISHER]