Modal noise in an integrated photonic lantern fed diffraction-limited spectrograph

In an attempt to develop a streamlined astrophotonic instrument, we demonstrate the realization of an all-photonic device capable of both multimode to single mode conversion and spectral dispersion on an 8-m class telescope with efficient coupling. The device was a monolithic photonic spectrograph which combined an integrated photonic lantern and an efficient arrayed waveguide grating device. During on-sky testing, we discovered a previously unreported type of noise that made spectral extraction and calibration extremely difficult. The source of the noise was traced to a wavelength-dependent loss mechanism between the feed fiber's multimode near-field pattern and the modal acceptance profile of the integrated photonic lantern. Extensive modeling of the photonic components replicates the wavelength-dependent loss, and demonstrates an identical effect on the final spectral output. We outline that this could be mitigated by directly injecting into the integrated photonic lantern.

Nineteen-port photonic lantern with multimode delivery fiber

We demonstrate efficient multimode (MM) to single-mode (SM) conversion in a 19-port photonic lantern with a 50 μm core MM delivery fiber. The photonic lantern can be used within the field of astrophotonics for coupling MM starlight to an ensemble of SM fibers in order to perform fiber-Bragg-grating-based spectral filtering. An MM delivery fiber spliced to the photonic lantern offers the advantage that the delivery fiber guides the light from the focal plane of the telescope to the splitter. Therefore, it is no longer necessary to have the splitter mounted directly in the focal plane of the telescope. The coupling loss from a 50 μm core MM fiber to an ensemble of 19 SM fibers and back to a 50 μm core MM fiber is below 1.1 dB.

THE VIRUS OF INFECTIOUS FELINE AGRANULOCYTOSIS : II. IMMUNOLOGICAL RELATION TO OTHER VIRUSES

The infection of cats by the virus of infectious feline agranulocytosis is followed by the production of specific neutralizing and protective antibodies, and recovery from the disease is associated with the development of solid immunity to reinfection. From the evidence presented it is obvious that the virus is not related to the viruses of hog cholera, lymphocytic choriomeningitis, fox encephalitis, vesicular stomatitis, the Western type of equine encephalomyelitis, herpes, and B virus infection.

THE VIRUS OF INFECTIOUS FELINE AGRANULOCYTOSIS : I. CHARACTERS OF THE VIRUS: PATHOGENICITY

Thirty-two strains of an infectious filterable agent, with properties that establish it as a virus, have been isolated from a malady of cats. This disease can be readily recognized and differentiated from other feline diseases by blood studies, which make apparent the characteristic profound leucopenia and marked relative lymphocytosis in the absence of thrombopenia and appreciable anemia. (Because the cytological pictures of the bone marrow and blood are essentially similar to those which characterize human agranulocytosis, we have named the disease under study "infectious feline agranulocytosis.") The cytological reaction to the presence of the virus is further characterized by proliferation of the reticuloendothelial cells of the lymph nodes and spleen, and by the formation of intranuclear inclusion bodies in the cells of the gastro-intestinal mucosa, lymph nodes, and bronchial mucosa. The etiological agent, the virus of infectious feline agranulocytosis, is pathogenic for cats when given by the oral, intragastric, cutaneous, subcutaneous, intraperitoneal, intravenous, and intranasal routes; it can be recovered at the height of the disease from the blood, spleen, liver, lung, intestinal mucosa, nasal secretions, nasal mucosa and turbinates, feces, and urine. The virus appears to be limited in its pathogenicity to the feline species. We found that a variety of animals, as represented by albino Swiss mice, guinea pigs, domestic rabbits, and ground squirrels (Citellus richardsonii Sabine), failed entirely to react to the injection of massive doses of virus. Repeated attempts at infection of these animals regularly failed when the intranasal, intraperitoneal, subcutaneous, and intramuscular routes of inoculation were employed for single doses. The same was true when from four to six transfers in "blind" serial tissue passages were made. Moreover, attempts to propagate the virus on the chorio-allantoic membrane of the developing chick were unsuccessful. The significance of the facts is discussed in the paper that follows.

Characterization and on-sky demonstration of an integrated photonic spectrograph for astronomy

We present results from the first on-sky demonstration of a prototype astronomical integrated photonic spectrograph (IPS) using the Anglo-Australian Telescope near-infrared imaging spectrometer (IRIS2) at Siding Spring Observatory to observe atmospheric molecular OH emission lines. We have succeeded in detecting upwards of 27 lines, and demonstrated the practicality of the IPS device for astronomy. Furthermore, we present a laboratory characterization of the device, which is a modified version of a commercial arrayed-waveguide grating multiplexer. We measure the spectral resolution full-width-half-maximum to be 0.75 +/- 0.05 nm (giving R = lambda/deltalambda = 2100 +/- 150 at 1500 nm). We find the free spectral range to be 57.4 +/- 0.6 nm and the peak total efficiency to be approximately 65%. Finally, we briefly discuss the future steps required to realize an astronomical instrument based on this technology concept.

The PLATO Dome A site-testing observatory: power generation and control systems

The atmospheric conditions above Dome A, a currently unmanned location at the highest point on the Antarctic plateau, are uniquely suited to astronomy. For certain types of astronomy Dome A is likely to be the best location on the planet, and this has motivated the development of the Plateau Observatory (PLATO). PLATO was deployed to Dome A in early 2008. It houses a suite of purpose-built site-testing instruments designed to quantify the benefits of Dome A site for astronomy, and science instruments designed to take advantage of the observing conditions. The PLATO power generation and control system is designed to provide continuous power and heat, and a high-reliability command and communications platform for these instruments. PLATO has run and collected data throughout the winter 2008 season completely unattended. Here we present a detailed description of the power generation, power control, thermal management, instrument interface, and communications systems for PLATO, and an overview of the system performance for 2008.

Examination of the relationship between African American adolescents' condom use at sexual onset and later sexual behavior: implications for condom distribution programs

School-based condom distribution programs have generated considerable controversy across the country. In the present study 249 sexually active African American adolescents who did (n = 119) and did not (n = 130) use a condom during their initial sexual experience were compared to assess whether condom use at the onset of sexual activity was associated with later differences in sexual behavior. The results indicated that youths who used a condom from the onset of sexual activity were more likely to have used a condom in the most recent intercourse occasion, less likely to be diagnosed with a sexually transmitted disease (STD) or to combine substance use with sexual activity, endorsed more positive attitudes toward condoms, and were older when they initiated sexual activity. The findings have implications for condom availability programs and indicate that initial condom use was not associated with earlier onset of sexual activity and was associated with higher rates of precautionary behavior among sexually active minority adolescents.

The predictive validity of a resident selection system

This paper describes a new system for resident selection that uses a descriptive rating scale and a microcomputer to create a rank order list for the National Resident Matching Program. The methods utilized to analyze the time efficiency, interrater reliability, and predictive validity of the system are reported. Interrater reliability was found to be high. The rank list was shown to correlate with both clinical performance of Pl-1 and Pl-2 pediatric residents and the American Board of Pediatrics In-training Examination. Correlations for the Pl-2 year were stronger than for the Pl-1 year.

A family survey of lupus erythematosus. 1. Heritability

First degree relatives and spouses of 36 patients with systemic lupus erythematosus (SLE) and 37 with discoid lupus erythematosus (LE) were assessed using the ARA criteria. They were compared with relatives and spouses of patients with other rheumatic and related complaints. Definite SLE was present in 3.9% of relatives of SLE probands, 2.6% of discoid relatives and 0.3% of controls. Discoid LE was diagnosed in 0.6% of SLE and 3.5% of discoid families compared with 0.5% of controls. None of the spouses of LE probands had SLE or discoid LE. The data gave the best fit for a polygenic inheritance with a heritability of 66 +/- 11% for SLE and 44 +/- 10% for discoid LE. Genetic factors are thus less important in SLE and discoid LE than in generalized osteoarthritis, spondylitis or gout with heritabilities of 90, 72 and 90%, respectively.

Radiological cervical arthritis in populations

The prevalence of cervical rheumatoid arthritis and its relationship to rheumatoid serum factors and erosive arthritis in peripheral joints has been studied in radiographs of the cervical spine and of the hands and feet drawn from 12 population samples. The changes were graded in accordance with the Atlas of Standard Radiographs of Arthritis. Rheumatoid arthritis of the cervical spine (grades 2-4) was observed in 4.1% of males and 4.7% of females aged 15 and over. Prevalence was greatest in those born before 1900, 15% of whom were affected. There was a significant association with the sheep cell agglutination test but not with the bentonite flocculation test, though the latter correlated well with erosive arthritis in the joints of the hands and feet. Arthritis of the cervical spine showed a significant correlation with both seropositive and seronegative erosive arthritis in the peripheral joints. A significantly higher prevalence of cervical arthritis than expected was noted in two population samples, one in Germany and the other in West Africa, though in neither was there a high prevalence of peripheral arthritis. The German population had relatively high antistreptolysin titres. A low prevalence of cervical arthritis was noted in populations in Czechoslovakia and in Arizona. 'Congenital' block vertebra had a prevalence of 0.9% in persons born before 1935, but none was observed in those born since. The figures suggest that environmental influences predisposing to cervical arthritis and block vertebra have changed in the last 40 years.

Osteoarthrosis in a rural South African Negro population

The prevalence and distribution of osteoarthrosis has been studied in a South African Negro population. One or more joints were affected in 60% of the males and 48% of the females, compared with a prevalence of 55% in males and 63% in females in a comparable English population. Multiple osteoarthrosis was significantly less common in the African than in the English population, the difference here being greatest in females. Clinical Heberden's nodes were also very infrequent in the African population. However, the Tswana males had significantly more osteoarthrosis of the metacarpophalangeal and proximal interphalangeal joints than was encountered in English males. This is attributed to the traumatic effect of hard manual work which is carried on into old age among most African populations.

Comparative toxicity of gold preparations in treatment of rheumatoid arthritis

Patients with rheumatoid arthritis have been treated alternately with aurothioglucose and aurothiomalate. In the earlier part of the study an oily suspension of aurothioglucose and an aqueous solution of aurothiomalate were used, but later an aqueous solution of aurothioglucose was alternated with the oily suspension and an oily suspension of aurothiomalate with the aqueous solution. Skin eruptions, stomatitis, and albuminuria were significantly more common in patients treated with the aqueous solution than with the oily suspension.

Rheumatic disorders in the South African Negro. Part II. Osteo-arthrosis

The prevalence of osteo-arthrosis of the hip, the knee, the small joints of the hand and the metatarsophalangeal joint of the big toe, has been studied in a South African Negro population. The pattern of joint involvement differed considerably from that expected in a White population. Interphalangeal osteo-arthrosis was much less common in Black women than in White, and Heberden's nodes were seen in only 3 of 93 respondents who were over 65 years of age. Osteo-arthrosis of the metacarpophalangeal joints also, was less common in Black women than in White, but the Black men showed a much greater involvement than that seen in White men. As in White peoples, osteo-arthrosis of the metatarsophalangeal joint of the big toe was commoner in women than in men, but the over-all prevalence did not reach the high levels in Whites. Osteo-arthrosis of the knee was much commoner in the women than in the men; this was associated with a marked tendency to obesity in the older women. The hip joint which is a common site for osteo-arthrosis in Whites, was seldom affected in this Black population. It is clear from this study that the apparent rarity of certain forms of degenerative arthritis in the South African Negro is not owing to any inherent resistance to the disease, because osteo-arthrosis of certain joints, such as the knee in women and the metacarpophalangeal joints in men, is even more common in Blacks than in Whites. The differences encountered can, in many instances, be attributed to differences in occupation and life style in the two populations; but genetic factors, may also play a part in the sense that certain predisposing disorders, such as congenital subluxation of the hip, appear to be far less common in Blacks than in Whites.

Hypertension in relation to musculoskeletal disorders

Generalized osteoarthrosis was found to be significantly more common in older males with high than with low diastolic blood pressure. The excess of osteoarthrosis in those with hypertension was mainly in the hips, knees, carpometacarpal and metacarpophalangeal joints, and was independent of obesity in the hypertensive group. It was not associated with a higher cholesterol or uric acid level in the serum. Radiological evidence of avascular necrosis was present in 36% of males with osteoarthrosis of the hips and diastolic blood pressure above 100 mmHg, in 20% with a diastolic pressure of 81-100 mmHg, but was found in none of those with osteoarthrosis and blood pressure of 80 mmHg or below. Only those with osteoarthrosis and a diastolic pressure above 100 mmHg had significantly more avascular necrosis that expected. Osteoarthrosis of the knee in female was more frequent in the hypertensive groups independent of obesity. It is concluded that vascular disorders are involved in this form of generalized osteoarthrosis.

Rheumatoid factor in the United Kingdom. II. Associations with certain infections

Persons having positive tests for rheumatoid serum factors in population samples in Leigh (Lancashire) and Wensleydale (Yorkshire) were investigated for evidence of infection. Comparison was made with seronegative persons and with persons having doubtful titres matched by age and sex with the seropositive groups.

Routine cultures were made of throat swabs and mid-stream specimens of urine were also cultured. The blood serum was assayed for ASO in both populations but for salmonella and Brucella abortus antibodies only in Leigh. The latex fixation test (LFT) was tested in both samples on the follow up but initially only in Wensleydale.

There was a significant association between the results of the sheep cell agglutination test and radiological evidence of sinusitis. Salmonella or brucella antibodies were associated significantly with a positive or doubtful sheep cell agglutination test. There was no association with the presence of haemolytic streptococci in the throat. The mean ASO titre showed some relationship to the sheep cell agglutination test in Leigh but not in Wensleydale.

The latex fixation test showed no significant association with any of the infections studied but the number with positive tests was small. Higher bacterial counts were obtained in the urine of both sheep cell agglutination (SCAT) and LFT positive than in seronegative individuals but the differences were not significant.

There was no significant association between arthritis and any of the infections studied.

Of those with a positive SCAT at the final test, 41% had rheumatoid arthritis, 24% had evidence of salmonella or brucella infection, 15% had sinusitis, 3% tuberculosis and 3% influenza.

Rheumatoid serum factor in populations in the U.K. I. Lung disease and rheumatoid serum factor

In population samples in England and Wales a greater frequency of positive sheep cell agglutination tests has been found in Leigh and the Rhondda than in Wensleydale, the Vale of Glamorgan or Watford.

The urban population of Leigh had more X-ray evidence of lung pathology than the rural population of Wensleydale. Seropositive persons in both the urban populations of Leigh and the Rhondda and the rural populations of Wensleydale and Glamorgan had more X-ray evidence of lung pathology than seronegative individuals, the difference being significant for healed tuberculosis of the lungs, thickened basal pleura and increased basal vascular markings. The association between the first two and rheumatoid factor was equally present in those with and without arthritis but in the third it was limited to those with arthritis. A history of bronchitis was no more common in persons with a positive sheep cell test than in those with a negative test and the indirect maximum breathing capacity showed no significant relationship to rheumatoid factor titre.

No association was found between cigarette smoking and the sheep cell titre.

It is concluded that parenchymal lung and pleural disease may act as a stimulus to the production of rheumatoid serum factor and that this stimulus is independent of the presence or absence of arthritis.

Heberden Oration, 1969. Rheumatoid arthritis--nature or nurture?

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Disc degeneration. Its frequency and relationship to symptoms

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