The expanding fireball of Nova Delphini 2013.

A classical nova occurs when material accreting onto the surface of a white dwarf in a close binary system ignites in a thermonuclear runaway. Complex structures observed in the ejecta at late stages could result from interactions with the companion during the common-envelope phase. Alternatively, the explosion could be intrinsically bipolar, resulting from a localized ignition on the surface of the white dwarf or as a consequence of rotational distortion. Studying the structure of novae during the earliest phases is challenging because of the high spatial resolution needed to measure their small sizes. Here we report near-infrared interferometric measurements of the angular size of Nova Delphini 2013, starting one day after the explosion and continuing with extensive time coverage during the first 43 days. Changes in the apparent expansion rate can be explained by an explosion model consisting of an optically thick core surrounded by a diffuse envelope. The optical depth of the ejected material changes as it expands. We detect an ellipticity in the light distribution, suggesting a prolate or bipolar structure that develops as early as the second day. Combining the angular expansion rate with radial velocity measurements, we derive a geometric distance to the nova of 4.54 ± 0.59 kiloparsecs from the Sun.

Epidemiological aspects of acute childhood poisoning among patients attending a hospital at Kolkata.

A retrospective study from a tertiary care teaching hospital in Kolkata revealed 3.6% of total paediatric admissions were due to poisoning. Majority of the cases included oral/chemical poisoning followed by biological/envennomation. Kerosene was the commonest among all poisoning. Most of the cases were accidental.

Immunization of crossbred cattle (Bos indicus x Bos taurus) with fractionated midgut antigens against Hyalomma anatolicum anatolicum.

Crossbred calves (Bos indicus x Bos taurus) were immunized with a fractionated midgut supernate antigen (GS-F Ag from Hyalomma anatolicum anatolicum). The first inoculation on day 0 was given intramuscularly after emulsification with Freund's complete adjuvant; the second was given subcutaneously on day 14 in incomplete Freund's adjuvant; and the third on day 35 was given subcutaneously without adjuvant. Each injection comprised 1 mg of antigen protein. Ten days after the last inoculation, the immunized calves were challenged simultaneously with 1000 larvae and 20 pairs (20 males and 20 females) of adult H. a. anatolicum on one ear and a similar number of Hyalomma dromedarii ticks on the other ear. There was a significant decrease in the percentage larval engorgement and larval rejection of up to 34% on the immunized calves. A significant increase in the engorgement and preoviposition periods and a significant decrease in the engorged weight, egg mass weight and reproductive index were observed for adult female ticks when fed on the immunized calves. The GS-F Ag also induced a considerable degree of cross-protection in calves against H. dromedarii larval ticks.

Immune responses in chickens against Eimeria tenella sporozoite antigen.

Two-day old broiler chicks were subcutaneously immunized with Eimeria tenella sporozoite antigen (25 microg per chick) with or without adjuvants on 2 and 18 days of age and the effect of induced immunity was determined by challenging the chickens with 10(4) homologous sporulated oocysts at 32 days of age. Chicks immunized with sporozoite antigen emulsified in Freund's Complete Adjuvant (FCA) showed protection in terms of oocyst production, mortality and mean lesion scores. Antigen emulsified in FCA produced significant cell mediated immune responses (as assessed by lymphocyte migration inhibition test) from 12 to 30 days post-immunization. Antibody responses as assessed by enzyme linked immunosorbent assay were significant from 12 days postimmunization when the antigen was administered with or without adjuvants by subcutaneous route.

A study of mycetoma in eastern India.

Forty consecutive cases of mycetoma were studied with respect to clinico-epidemiological, histopathological and radiological features. The age of the patients ranged from 17 to 57 years mean being 32.4 +/- 8.68. The disease was equally distributed amongst the sexes. Most of the patients had a rural background and the disease occurred mainly among farmers and housewives. Actinomycetes (32 cases. 80%) were found to be the main pathogenic organism and Eumycetes in 4 cases (20%) only. Clinical features were more or less the same irrespective of the aetiologic agent, consisting of local swelling with discharging sinuses. History of trauma was present in only 20% cases and 80% were incidental. Foot (28/40 i.e. 70%) was the commonest site of infection. Radiological bony involvement was detected in 14 out of 18 cases examined (38.88%). Out of the 32 radiographed patients of actinomyetoma 10(31.25%) showed bony involvement whereas all the four. Eumycetoma cases radiographed, had bony involvement. The notable bony changes were sclerosis, erosions, periosteal thickening and osteoporosis.

Immunization of cattle with nymphal Hyalomma anatolicum anatolicum extracts: effects on tick biology.

Antigens derived from partially engorged nymphs of Hyalomma anatolicum anatolicum were used in immunizing crossbred (Bos indicus x Bos taurus) cattle against larval, nymphal and adult H. a. anatolicum and H. dromedarii. The cattle were either infected with Theileria annulata at low parasitaemia or were uninfected. Whole nymphal extract (WNE), nymphal membrane antigens (NMA) and nymphal soluble antigens (NSA) were used for immunization. The group immunized with WNE showed significant and better rejection of H. a. anatolicum ticks as compared to calves immunized with either NMA or NSA. The moulting rates of both engorged larvae and nymphs remained unaffected. Nymphs which engorged on the immunized calves were fully susceptible to infection by T. annulata as indicated by the intensity and abundance of Theileria infections in the resulting adult ticks from immunized and unimmunized Theileria infected cattle. These ticks also transmitted fatal theileriosis to susceptible calves.

Improving the accuracy of the caustic test.

The caustic or Gaviola test, used for testing aspheric mirrors, has been studied with reference to the research of Schroader ["The caustic test," in Amateur Telescope Making III, A. G. Ingalls, ed. (Kingsport Press, Kingsport, Tenn., 1953), pp. 429-456]. It is shown that the two central formulas, which are used to determine the mirror quality, give significant errors for the large-diameter, short-focal-length mirrors commonly used in astronomical optics. We derive analytically two alternative equations, which are more exact, and show that they lead to significant improvement.

Comparison of the post-parturient rise in faecal egg counts of indigenous and cross-bred ewes.

The breed differences in post-parturient rise (PPR) in faecal egg counts in lambing ewes of different breeds naturally infected with Haemonchus contortus were compared. The ewes of Nali, 50% Nali x 50% Russian Merino/Corriedale and 37.5% Nali x 62.5% Russian Merino/Corriedale were treated with fenbendazole while ewes of the above three breeds as well as 25% Nali x 75% Russian Merino/Corriedale, were kept untreated. Observations from 3 weeks before lambing to 12 weeks post-lambing at weekly intervals revealed that in treated ewes, egg counts of Nali did not differ significantly with 50% Nali whereas 37.5% Nali had significantly higher egg counts than those of Nali and 50% Nali. In untreated ewes egg counts of 50% Nali were significantly higher than that of Nali on some occasions, while 25% Nali had significantly higher egg counts than the other three breeds. None of the ewes from the Nali breed showed signs of haemonchosis, whereas few lambing ewes of the three Nali crosses (50%, 37.5% and 25% Nali) showed signs of haemonchosis and one ewe of the latter breed died.

Susceptibility of two crossbreeds of sheep to Haemonchus contortus.

Studies were conducted on 20 crossbred lambs of 4-5 months old. Ten lambs were Nali x Corriedale cross (Hisardale) and the other 10 were Nali x Lohi cross (Munjal). Seven lambs each of both crossbreeds were infected with 10,000 infective larvae of Haemonchus contortus. Three lambs of each crossbreed served as uninfected controls. Clinicopathological examinations were done before and after infection and all the lambs were necropsied 28 days post-infection. The body weight gain, haemoglobin and packed cell volume were significantly lower in Hisardale lambs and the peripheral eosinophil count was significantly higher in Munjal lambs. Significant hypoalbuminaemia and hypoglobulinaemia, a sharp increase in albumin: globulin ratio; significantly higher faecal egg counts; adult worm counts; abomasal pH, volume, congestion and oedema were observed in Hisardale lambs as compared to Munjal lambs. Clinical signs of haemonchosis were more severe in Hisardale lambs and two of them died. Munjal lambs therefore seem less susceptible than Hisardale lambs to H. contortus infection.

Effects of immunization of rabbits on establishment, survival, and reproductive biology of the tick Hyalomma anatolicum anatolicum.

Four antigenic preparations, viz. salivary gland antigen (SG Ag), whole tick extract antigen (WTE Ag) and 30,000-g supernatant fraction, and pellet of WTE Ag (TES Ag and TEP Ag, respectively), were made from partially fed adult female Hyalomma anatolicum anatolicum. Four groups of 5 rabbits each were immunized with the antigens, and a fifth group was kept as control. Following challenge with adult H. a. anatolicum, a significant decrease in engorgement weight and egg mass weight and an increase in engorgement period and preoviposition period were observed in WTE Ag-immunized rabbits. Similar results were observed with TES Ag and SG Ag, except that change in the engorgement period was insignificant. However, none of the tick parameter measurements showed significant changes with TEP Ag. None of the antigens produced significant changes in the percentage of engorgement or oviposition period of the challenged ticks. Thus, WTE Ag was the most effective in altering tick performances.

Attempted immunisation of crossbred calves (Bos taurus x Bos indicus) by repeated natural attachment of ticks Hyalomma anatolicum anatolicum Koch (1844).

Crossbred calves (Bos taurus x Bos indicus) were repeatedly infested with the ixodid tick, Hyalomma anatolicum anatolicum. The parameters of engorgement, pre-oviposition period, oviposition period, engorged weight, egg batch weight, and per cent hatch of eggs all showed statistically significant differences between first to tenth infestation. Only the time to engorgement did not change. It is concluded that repeated infestations of this tick stimulate acquired resistance.

Immunization of cattle (Bos indicus X Bos taurus) against Hyalomma anatolicum anatolicum using antigens derived from tick salivary gland extracts.

Studies were conducted on 41 cross-bred (Bos taurus x Bos indicus) calves which were less than 1 year old. Three types of salivary gland antigens (SG Ag) viz. SG Ag-I (whole), SG Ag-II (supernatant) and SG Ag-III (sediment), prepared from the ixodid tick, Hyalomma anatolicum anatolicum, were used for immunizing these calves. The calves were divided into five groups. The first three groups were immunized with SG Ag-I, -II and -III with Freund's complete adjuvant (FCA), respectively. The fourth group was immunized with SG Ag-I (without adjuvant), and the fifth group remained as an unimmunized control inoculated with FCA only. In all the groups, immunization was carried out on days 1 and 14 and the animals were challenged on the 21st day. Significant resistance developed in the calves of the SG Ag-I and SG Ag-II (both with FCA) groups. Of all, SG Ag-I with FCA proved the most potent immunogen. Both humoral and cellular immune responses were demonstrated by in vivo and in vitro tests. The capillary tube agglutination test and double diffusion test gave positive reactions 21 days after first immunization. The immunized calves showed a significant increase in the levels of serum gamma globulin and per cent 'E' rosettes. Tick salivary gland antigens therefore seem to have promising potentials in inducing resistance in calves.

Cell-mediated immune response in anaplasmosis in cattle.

The cell-mediated immune response (CMIR) was demonstrated during experimental Anaplasma marginale infection in cattle, in vivo by the intradermic skin test and in vitro by the leucocyte migration inhibition test (LMIT). The skin test showed a delayed hypersensitivity reaction which reached its maximum after 48-72 hours. Histopathological examination of the skin biopsies revealed excessive infiltration by mononuclear cells and accumulation of oedematous fluid in the deeper dermal layers. For LMIT, the particulate antigen was used and the inhibition of leucocyte migration was significant in vaccinated and carrier animals as compared to controls.