Temporal evolution of electron cloud in a cylindrical Penning trap at room temperature.

The temporal evolution of the electron cloud at room temperature has been recorded through a resonance circuit by observing the axial oscillation frequency of its center of mass. The electron cloud undergoes radial expansion by interacting with the residual gas molecules, and it is finally lost upon hitting the Penning trap electrodes. It has been confirmed through detailed experimental investigations that the unique temporal pattern of frequency variation is a consequence of the cloud's radial expansion. Consequently, this approach offers a non-destructive means for single-shot detection, enabling continuous monitoring of the electron cloud's radial expansion during the confinement time. This technique offers a significant advantage over its destructive alternatives.

Design of a helical resonator with improved figure of merit.

A helical resonator serves as a key element for the detection of the trapped charged particles in a Penning trap. In order to compare the performance of the helical resonators, the concept of figure of merit (FOM) was introduced by Ulmer et al. [Nucl. Instrum. Methods Phys. Res., Sect. A 705, 55-60 (2013)]. In this work, we optimized the geometrical parameters of a resonator by numerical simulations keeping its outer dimensions and the diameter of the copper wire fixed and obtained the best possible value of FOM under these constraints. The corresponding 95 MHz helical resonator has been designed and fabricated, and its measured value of FOM is in good agreement with the simulated values. An empirical relationship between the total length of the wire to make the helical coil and the resonance frequency has been obtained. The simulations show that the FOM increases considerably with the increase in the conductivity of the building material, and this would be useful in detecting the feeble trap signal in cryogenic environment.

Fabrication of non-magnetic multi-pin coaxial vacuum feedthrough system for cryogenic applications.

We have developed and tested a compact non-magnetic feedthrough made of epoxy resin and capable of maintaining vacuum leak tightness over a wide temperature range (300 K-4 K). It is equipped with 15 electrical pins and three 50 Ω coaxial lines. The feedthrough has been designed to apply a high voltage (up to 5 kV) and transmit radio-frequency signals for operating a Penning trap over a wide temperature range (300 K-4 K). The characteristic impedances of the coaxial lines have been measured at 300 K and 77 K and found to remain ∼50 Ω over the frequency range of our interest (10 MHz-80 MHz). The details of its fabrication and performance over a wide temperature range have been discussed.

Prevalence of Deg Nala disease in eastern India and its reproduction in buffaloes by feeding Fusarium oxysporum infested rice straw.

OBJECTIVE: To undertake a study on prevalence of Deg Nala disease in eastern states of India and to reproduce the disease in buffaloes by the Fusarium spp., isolated from the affected region. METHODS: During this investigation, a survey was conducted covering four states of eastern region to identify the Deg Nala cases as well as to isolate and characterize the causative agent(s). An experimental study was carried out to reproduce the disease in healthy male buffaloes (2-3 years age) by randomly dividing them into five groups (four in each group). Each individual group was fed with rice straw artificially infested with either of the two representative isolates of Fusarium oxysporum (F. oxysporum) (F01, F02) or representative reference strains of Fusarium equiseti (F. equiseti) (ITCCF-2470) and Fusarium moniliforme (F. moniliforme) (ITCCF-4821) for 30 days, whereas the control group was fed with normal rice straw only. RESULTS: A total of 658 Deg Nala cases were recorded and 12 Fusarium isolates were identified from the mouldy rice straw collected from these affected areas. The characterization of the isolates revealed three species viz., F. oxysporum, F. equiseti and F. moniliforme, among which F. oxysporum was predominant. The disease was artificially reproduced in three buffaloes in F01 group and one in F02 group within 20-23 days by feeding F. oxysporum infested rice straw which resembled the clinical symptoms and gross lesions of natural Deg Nala cases. CONCLUSIONS: The field investigation and laboratory studies, including experimental production of Deg Nala disease suggest the possible involvement of mycotoxins. However, further investigations needs to be done to understand nature of the toxic factors involved in production of the Deg Nala disease.

Benign laryngopharyngeal lesions: a case series.

Benign neoplasms of the laryngopharynx are extremely rare. Hereby we present 3 such interesting cases managed at our institute. While one was managed by conventional endoscopic route the other two required external approach. Even in the present era of endoscopic surgery sometimes these lesions necessitates external approach owing to anatomical distortion causing difficulty in intubation and/or inadequate exposure of the lesion. All these cases highlights the need of a competent surgeon to treat benign laryngopharyngeal lesions.

Giant fibrous epulis.

A variety of swellings located on or near the gums is clinically included under the heading of epulis. There are various types of epulis. In today's era of super specialization gum swellings more commonly present to the dental surgeon than to the practicing otolaryngologist. We present an interesting case of a fibrous epulis managed in our institute along with a brief review of literature.

Olmsted syndrome.

Olmsted syndrome is a rare disorder characterized by symmetrical sharply marginated mutilating keratoderma of palms & soles & hyperkeratotic plaques around the body orifices, onychodystrophy, ainhum & amputation of digital phalanges, flextion deformities of the fingers, localized alopecia, leukokeratosis of the tongue, shortness of stature & laxity of large joints. Inheritance is autosomal dominant, although sporadic cases have been reported. Here we describe two cases of this rare disorder with thickened hyperkeratotic lesion over palm & soles & along with amputation of 3rd , 4th & 5th toes in one case. In one of our case (case no. 2) the immediate younger brother has got the same disease. Both of them were treated with tab. Neotegason 25 mg orally daily for 3 months & there was significant improvement after treatment.

An interesting case of arterio-veinous malformation in the neck.

An arterio-veinous malformation can be acquired and is rarely congenital. It usually presents with cosmetic deformity. If large it may manifest features of haemodynamic changes. Clinical assessment is the mainstay of diagnosis. Arteriography, MR angiography and rarely histopathology may help in clinching the final diagnosis. It is treated with wide excision after ligation of feeder vessels. Herein we present one such case of arterio-veinous malformation with review of available literature.

Dairy farm investigation on Shiga toxin-producing Escherichia coli (STEC) in Kolkata, India with emphasis on molecular characterization.

An investigation was conducted to determine the distribution, virulence gene profile and phenotypes of Shiga toxin-producing Escherichia coli (STEC) strains within a dairy farm in Kolkata, India by characterizing the STEC strains isolated from healthy dairy cow and calf stool samples, raw milk and farm floor swabs from July 2001 to March 2002. Primary screening by multiplex-PCR detected stx1 and stx2, the common virulence genes of STEC, in 18.9% of cow faeces, 32.4% of calf stool samples, 21.6% of farm floor swabs and 4.5% of raw milk samples and viable STEC were recovered from 4.5, 9.9, 8.1 and 1.8% of the corresponding PCR-positive samples. Strains harbouring stx1 (63.3%) and hlyA (53.3%) were frequently detected compared to eae (13.3%). Most of the strains harboured similar sets of reported virulence genes common among isolates from diarrhoea patients. Most of the strains also exhibited multidrug resistance, sorbitol fermentation and produced enterohaemolysin. The randomly amplified polymorphic DNA-PCR (RAPD-PCR) profile of the STEC strains isolated from the farm milieu revealed diverse banding patterns and clonal analysis demonstrated that the strains from different sources were not identical but showed some genetic relatedness. The study demonstrates the potential of dairy farm for housing virulent STEC.

Endoscopic removal of malignant melanoma of the nasal cavity.

Mucosal melanoma of the nasal cavity is a rare tumour. With the extended used of nasal endoscopes and advent of CT scan, early diagnosis of nasal melanoma and accurate assessment of its extent is possible. This allows endoscopic excision of tumour, avoiding unnecessary removal of healthy tissue. Here we present a case where endonasal endoscopic excision with postoperative radiotherapy achieved disease free survival till follow up (nearly 2 years).

Antibiotic resistance, virulence gene, and molecular profiles of Shiga toxin-producing Escherichia coli isolates from diverse sources in Calcutta, India.

Antibiotic resistance, virulence gene, and molecular profiles of Shiga toxin-producing Escherichia coli (STEC) non-O157 strains isolated from human stool samples, cow stool samples, and beef samples over a period of 2 years in Calcutta, India, were determined. Resistance to one or more antibiotics was observed in 49.2% of the STEC strains, with some of the strains exhibiting multidrug resistance. The dominant combinations of virulence genes present in the strains studied were stx(1) and stx(2) (44.5% of strains) and stx(1), stx(2), and hlyA (enterohemorrhagic E. coli hemolysin gene) (19% of strains). Only 6.4% of the STEC strains harbored eae. The diversity of STEC strains from various sources was assessed by random amplification of polymorphic DNA (RAPD). STEC strains that gave identical or nearly similar DNA fingerprints in RAPD-PCR and had similar virulence genotypes were further characterized by pulsed-field gel electrophoresis (PFGE). Identical RAPD and PFGE profiles were observed in four sets of strains, with each set comprising two strains. There was no match in the RAPD and PFGE profiles between strains of STEC isolated from cows and those isolated from humans. It appears that the clones present in bovine sources are not transmitted to humans in the Calcutta setting although these strains showed evolutionary relatedness. Maybe for this reason, STEC has still not become a major problem in India.

An outbreak of gangrenous syndrome among buffaloes and cattle in West Bengal: clinicopathological studies.

Gangrenous syndrome/Degnala disease was recorded in a large number of buffaloes and cattle in Murshidabad district of West Bengal, India. Fusarium spp. had been isolated from the mouldy paddy straw which were fed to the animals. There was a reduction in the incidence of the disease following withdrawal of the mouldy paddy straw. Histopathological examination showed necrosis and loss of architectural details in the skin.

Capillaria hepatica, a parasite of zoonotic importance--a brief overview.

This review briefly elucidates the biology and mode of transmission of the parasite capillaria hepatica, an cuimial parasite. Occasional transmitted to man.

Dermatophytes isolated from selected ruminants in India.

A survey was carried out in different areas of Uttar Pradesh for isolating and identifying dermatophytes from ruminants. Out of 102 skin scrapings, collected from various animals, 4/22 cattle, 1/9 buffalo, 14/44 sheep and 2/28 goats were KOH positive. In respect of the cattle, the culture positive samples yielded one strain each of Trichophyton mentagrophytes, T. rubrum, T. simii and two strains of Microsporum gypseum. From the buffaloes examined, only one case yielded a dermatophyte and it was identified as T. mentagrophytes. In respect of the sheep, two samples were culture positive and the dermatophyte was T. mentagraphytes (2). Of the 28 goat scrapings, only two harboured dermatophytes viz., M. gypseum and T. mentagrophytes. Fungi other than dermatophytes isolated from the ruminants were Alternaria species, Aspergillus species, Beauveria bassiana, Chrysosporium keratinophilum, Curvularia species, Penicillium species, Pseudoarachniotus roseus and T. terrestre. Isolation of T. rubrum from the skin lesion of one of the cattle is noteworthy, since this dermatophyte is better known as an anthrophilic species.

A modified needle to apply circumferential wires.

Circumferential wiring is executed by various awls and needles. A method is presented by which a needle can be easily transformed into an awl.

Invasive pulmonary pseudallesheriosis in a cross-breed calf.

Pulmonary pseudallescheriosis was diagnosed in a two-months old calf. Pneumonic lungs with yellow-white nodules on the surfaces revealed granulomatous lesions microscopically. Septate, pleomorphic hyphae were present in the central caseated core with a bright eosinophilic periphery surrounded by polymorphonuclear cells and macrophages followed by a zone of epithelioid cells admixed with lymphocytes and plasma cells. The fungal agent was demonstrated by Grocott's silver methenamine staining. On isolation, morphologically it was found to be indistinguishable from that of Pseudallescheria boydii. It appears to be first report of fatal mycotic pneumonia in a calf due to P. boydii. The emphasis is given for further detailed investigation on this aspect in veterinary mycopathology.

Chrysosporium tropicum as a probable cause of mycosis of poultry in India.

Chrysosporium tropicum was isolated from comb lesions in two different breeds of chickens in India and subcultures were shown to be pathogenic when inoculated onto prepared skin of guinea pigs. This report provides additional evidence to consider Ch. tropicum as a pathogenic fungus and a probable cause of a dermatomycosis in chickens.

Rapid photometric assay of growth of Mycoplasma mycoides subsp. capri.

A new spectrophotometric technique for evaluation of early growth in liquid culture of Mycoplasma mycoides subsp. capri has been developed. As turbidity does not appear until after incubation to 18 h the method utilizes the change in absorbance of the medium at 550 nm to monitor growth. The change in absorbance of the medium (which contains phenol red) occurs when the pH changes due to microbial growth. For measurement of growth at later stages when turbidity is proportional to number of colony forming units, two other wavelengths (450 nm and 700 nm) have been suggested.

Isolation of Candida pseudotropicalis from cases of abortion among mares: a note.

PIP: Material from 13 cases of abortion in 1 epidemic outbreak of abortion among mares was pooled into 3 lots and injected intraperitoneally into 3 separate sets of mice. The mice died within 5-7 days. Tissues from each set of inoculated mice showed the presence of yeast-like bodies, and pooled material from each of the 3 lots also yielded the yeast in culture. Histopathological examinations of the mare placenta and fetal organs also revealed the presence of the yeast. The organisms appeared round or oval, thin-walled, and about 2-4 microns in diameter and were identified as Candida pseudotropicalis. Urease test was negative. Acid and gas formation was found within 3 days of incubation at 27 degrees C in glucose, lactose, and sucrose, but not in maltose.^ieng