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We undertook a prospective study of cytology and concurrent colposcopically directed biopsies of both Human Immunodeficiencey Virus seronegative (HIV-) and seropositive (HIV +) women at high risk for cervical intraepithelial neoplasia (CIN) to determine the accuracy of Pap smears in this population. Women were recruited from a sexually transmitted disease clinic and a women's prison in eastern Massachusetts. All were interviewed, blood was tested for HIV with CD4 counts done in 101 of the 102 HIV + women, and all received a pelvic exam that included a conventional Pap smear, a Thinprep test, and colposcopy with directed biopsies and endocervical curettage. A total of 184 women volunteered. 82 were HIV- and 102 were HIV+. The prevalence of CIN in HIV+ women was 37%, more than twice the 17% prevalence of CIN in HIV-women (P = 0.002). When Atypical Squamous Cells of Undetermined Significance (ASCUS) findings were included with "negative" cytology, the conventional Pap smear false negative rates for HIV- and HIV+ women were 21% and 37%, respectively. When ASCUS was included with "positive" cytology, the false negative rates dropped to 14.3% for HIV- women and 10.5% for HIV+ women. We conclude that ASCUS diagnoses comprised the majority of false negatives in HIV+ women.

Diagnostic technique and their associated hardware play an important role in evaluating high voltage /current pulsed power systems like present day Radar Transmitters, which operate at high voltages/currents. These diagnostic techniques can be used for on-line monitoring of important parameters of Radar Transmitter to ascertain its health during operation on pulse to pulse basis. In this paper, a typical radar transmitter is discussed in the light of these techniques. In radar transmitter, the most commonly used final power amplif- iers like Travelling Wave Tube (TWT), Klystron, Cross Field Amplifier (CFA) etc., operate at very high volta- ges, of the order of 50 KV and above. The tube paramet- ers such as filament voltage/current, beam voltage/ cu- rrent, tube bias voltages etc. are to be continuously monitored on pulse to pulse basis to ascertain that the tube is working at proper operating point. The techniques adopted for parameters (voltage/current) which are floating with respect to ground, bringing down these parametric values referenced to ground level for monitoring, comparison and to take a suitable action for fail-safe operation, are described and analysed. The effectiveness of these techniques are evaluated at higher Pulse Repetition Frequencies (PRF's) and at the operating voltage beyond 50 KV.

We hypothesized that patients with cystic fibrosis would have abnormal lithium handling because the genetic defect in cystic fibrosis encodes an ion channel which causes a generalized electrolyte transport disorder in epithelial membranes. Eight patients with cystic fibrosis and eight age-sex matched healthy subjects ingested 600 mg lithium carbonate and had urine and serum lithium levels assessed 24 h later. Compared with healthy subjects, the patients with cystic fibrosis had higher serum lithium levels (0.071 +/- 0.038 vs 0.113 +/- 0.055 mmol l-1, P = 0.03) and had lower fractional renal excretion of lithium (27.5 +/- 14.8 vs 18.8 +/- 9.3%, P = 0.03). Caution should be used in prescribing standard doses of lithium to patients with cystic fibrosis until more definitive data are available.

Near-field Cassegrainian antennas are of low noise and broadband characteristics compared to the standard Cassegrain antennas. This arrangement minimizes spillover of energy since a plane wave feed (conical horn-reflector) with good shield is used to illuminate co-focally placed primary & secondary paraboloidal reflecting surfaces. Paper describes complete design procedure of near-field Cassegrainian antennas. A design of such antenna is illustrated at 10 GHz frequency. Measurements of primary and secondary radiation pattern are shown and results are discussed.

Recently microwave latching circulators have gained significant importance, particularly in the fast switching applications, as these require low switching energy and have fast switching times (fraction of a microsecond). The main advantages of the latching device over the conventional circulators are elimination of the permanent magnets and provision of switching.In this paper ferrite fabrication techniques have been discussed and various indigenous ferrites (tested) are compared from the view point of their suitability in a latching device.

A generalized analysis of the non-planar dipole antenna with arbitrarily displaced feed-points is presented. This configuration is obtained by combining the two concepts, namely (i) the concept of inclined antenna, and (ii) concept of displaced feed-points. The specific features of this antenna configuration is that it acts as a source of complex radiation, i.e. the field radiated by the antenna gives three components of E-vector along the three orthogonal axes. Further, the effect of balanced and unbalanced feed as well as that of the feed-points displacement on the far field radiation patterns, radiation resistance, power gain, effective aperture and efficiency is evaluated. Typical plots and tables are given to elucidate the theoretical results. Some of the important applications of this configuration are also pointed out.

A generalized analysis of the non-planar dipole antenna with transversely displaced feed-points is presented. This configuration is obtained by combining the two concepts. namely (a) the concept of inclined antenna and (b) the concept of displaced feed-points. The specific features of this antenna configuration is that it acts as a source of complex radiation, i.e. the field radiated by the antenna has three E vectors along the three orthogonal axes. Further, the effect of balanced and unbalanced feed as well as that of the displacement of the feed-points on the far-field radiation pattern radiation resistance, power gain, effective aperture and efficiency is evaluated. Typical plots and tables are given to elucidate the theoretical results. Some of the important applications of this configuration are also pointed out.

This paper describes an experimental set up of a time division multiplexing (TDM) scheme developed for a 16-channel vocoder under development in the Audio and Acoustics Division of Central Electronics Engineering Research Institute, Pilani. A channel vocoder is a bandwidth compression system used for transmission of voice signals. In a channel vocoder the speech signal is continuously analysed at the transmitting end and is synthesized at the receiving end. The analyser consists of 16-spectrum channels, voicing-un-voicing indicator and a pitch extracting circuit. The spectrum outputs of the spectrum channels and pitch circuit are slowly varying d.c. signals. In order to send all the information on a single line, the signals from the 17 channels are time division multiplexed. After multiplexing the 16-spectrum channels are encoded by a 3-bit PCM encoder while the 17th channel (i.e. pitch channel) is encoded by a 6-bit PCM encoder. The encoded signals are then transmitted. On the receiving side a synchroniz...

Summary Thirteen cases of tuberculosis of the breast are recorded in a series of 433 patients with breast pathology admitted to the hospital. The ˦tiological, pathological and clinical features are discussed. Two clinical types of cases are distinguished, corresponding to the pathological types. The treatment is discussed in the light of modern specific anti-tuberculous therapy. The indications for surgical treatment are described and the necessity for modified surgery is discussed with the result of followed-up cases.

A new technique for compressing the beam of the log periodic dipole antenna with Ψ-0° is presented. An axially displaced half wave dipole antenna provides a narrower half power beam width as compared to the conventional half wave dipole antenna. Using this fact it is theoretically shown that the beam of the log periodic dipole antenna can be compressed by axially displacing the feed points of the constituent dipoles of the log periodic dipole antenna. Typical theoretical results are given for different values of axial feed displacement.

An approximate expression is derived for the phase velocity of wave propagation along an infinite Yagi structure with its conventional constituent dipoles replaced by short helices operating in their normal mode. It is theoretically predicted that the proposed infinite Yagi structure acts as a slow wave structure.

Theoretical results for the radiation resistance, power gain, effective aperture and efficiency of the modified log-periodic dipole antenna are presented. A comparison is made for these quantities between the conventional log-periodic dipole antenna and log-periodic dipole antenna with dipoles having axially displaced feed-points.

Schelkunoff's method of moments has been applied to calculate the radiation resistance of a center-fed dipole antenna with feed points displaced transverse to dipole axis and the results are compared with the conventional theoretical results and are found to be in good agreement. The method suggested is quite simple, fairly accurate, and straightforward.

A relation for the photon-magnon conversion efficiency in axially magnetized garnet delay line has been developed which is independent of the saturation magnetization and depends on the position of the turning point. Calculations have been made for the various positions of the turning point. The calculated result agrees with the experimental value.

Solid state microwave delay lines using single crystal yttrium iron garnet (YIG) have many advantages over the conventional types of microwave frequency delay lines using coaxial cables or waveguides. YIG is a material with extremely low loss. The delay of the order of few microseconds can be obtained in a delay line using YIG rod of about 1 cm. length. This paper deals with the conversion loss as a function of the location of the turning point.

A centre-fed dipole antenna with one arm inclined through an angle α1 to its axis (which lies along Z axis) in Y-Z plane and the other arm inclined by an angle α2 in X-Z plane is analysed. The far field analysis predicted that the radiated far field is multipolarised with E vectors along X, Y and Z axes.

Theoretical expressions for radiation resistance (R0), power gain (G), aperture (A) and efficiency (η), of the non-planer centre fed dipole antenna with one arm inclined, by an angle α1 to its axis (which lies along Z axis) in the Y-Z plane and the other arm inclined by an angle α2 in the X-Z plane, are derived. It is found that radiation resistance, power gain and efficiency are functions of α1 and α2.