Search

We have combined two low-threshold detector technologies to develop a large-mass, low-threshold detector system that simultaneously measures the athermal phonons in a sapphire detector while an adjacent silicon high-voltage detector detects the scintillation light from the sapphire detector. This detector system could provide event-by-event discrimination between electron and nuclear events due to the difference in their scintillation light yield. While such systems with simultaneous phonon and light detection have been demonstrated earlier with smaller detectors, our system is designed to provide a large detector mass with high amplification for the limited scintillation light. Future work will focus on at least an order of magnitude improvement in the light collection efficiency by having a highly reflective detector housing and custom phonon mask design to maximize light collection by the silicon high-voltage detector., 6 pages, 12 figures

Aim: Endophytic bacteria indigenous to carnivorous plants have been explored for production of novel bioactive metabolites including extracellular enzymes. Bacillus aerius UB02, an extracellular neutral protease producing isolate endophytic to bladder of Utricularia stellaris L. f. was used in this study. Methodology: The bacterial isolate UB02 was identified following morpholological, physiological, biochemical and 16S rRNA gene sequence analyses. The media as well as the cultural conditions for production of protease were optimized. The extracellular protease was isolated and purified from the cell-free culture filtrate by ammonium sulphate precipitation, dialysis and DEAE Sephadex ion exchange column chromatography and the optimum conditions for its activity were determined. Results: The isolate Bacillus aerius UB02 (GenBank accession no. MK 696417, MCC accession no. 4132), produced significant amount of extracellular protease (38.29 U mg-1 protein) during growth in casein supplemented synthetic medium. However, peptone yeast extract glucose medium appeared to be the best for the synthesis of enzyme. Production of enzyme was enhanced by the inoculum density of 1.5% (v/v), culture volume: flask volume (CVF) ratio of 1:10, substrate concentration of 2.5% (w/v) with temperature and pH adjusted at 37°C and 7.4, respectively. Glucose (2.2%, w/v) and ammonium chloride (1.2 g/L) as carbon and nitrogen sources also favoured the enzyme production. The neutral protease with a molecular weight of approximately 35 kDa showed maximum activity at 40°C, pH 7.8 with 2% (w/v) casein. The enzyme exhibited Km and Vmax values of 6.81 mg ml-1 and 62.5 U mg-1 of protein, respectively, and was moderately thermostable. The protease activity was inhibited by Pb and Cd as well as 1,10-phenanthroline and β-mercaptoethanol. Interpretation: These findings will help not only in understanding the role of endophytic bacteria and the enzymes produced by them in the digestion of prey by carnivorous plant but could also be explored for application in the field of biotechnology.

We report the fabrication and performance of an annular, cryogenic, phonon-mediated veto detector that can host an inner target detector, allowing substantial reduction in radiogenic backgrounds for rare event search experiments. A germanium veto detector of mass $\sim$500 g with an outer diameter of 76 mm and an inner diameter of 28 mm was produced. A 25 mm diameter germanium inner target detector of mass $\sim$10 g was mounted inside the veto detector. The detector was designed using inputs from a GEANT4 based simulation, where it was modeled to be sandwiched between two germanium detectors. The simulation showed that the background rates (dominantly gamma interactions) could be reduced by $>$ 90$\%$, and that such an arrangement is sufficient for aggressive background reduction needed for neutrino and dark matter search experiments. During testing at the experimental site the veto detector prototype achieved a baseline resolution of 1.24 $\pm$ 0.02 keV while hosting a functional inner target detector. The baseline resolution of the inner target detector was 147 $\pm$ 2 eV. The detectors were operated at mK temperatures. The experimental results of an identical detector arrangement are in excellent agreement with the simulation., 8 pages and 9 figures

The Metropolitan Water District of Southern California (Metropolitan) and the Sanitation Districts of Los Angeles County (Sanitation Districts) are exploring the potential of a Regional Recycled Water Program (RRWP) to beneficially reuse water currently discharged to the Pacific Ocean. The program would consist of a new advanced water treatment (AWT) facility at the Sanitation Districts' Joint Water Pollution Control Plant (JWPCP) in Carson, California, USA, capable of producing an ultimate flow of 581 MLD (150 MGD). The full-scale facility would treat effluent from the JWPCP using an AWT train comprising a membrane bioreactor (MBR), followed by reverse osmosis (RO) and ultraviolet light advanced oxidation (UV/AOP). After MBR-RO-UV/AOP treatment, the treated water would be distributed to groundwater basins in Los Angeles and Orange counties to recharge their aquifers. This program would diversify the region's water resources and significantly contribute to long-term water supply targets outlined in Metropolitan's Integrated Water Resources Plan. A feasibility study for the RRWP was completed in 2016, confirming its technical viability. Currently, Metropolitan and the Sanitation Districts recently completed conceptual planning studies to investigate implementation options for a full-scale program, and constructed a 1.9 MLD (0.5 MGD) AWT demonstration facility. Although large facilities employing membrane filtration (MF)-RO-UV/AOP are currently permitted and operating in California, there are no facilities using an MBR-RO-UV/AOP train. The AWT demonstration facility – the Regional Recycled Water Advanced Purification Center – will build on recent research in Australia and the USA to develop a regulatory strategy to incorporate MBR into a potable reuse advanced treatment train.

Extreme ultraviolet (EUV) induced pulsed plasma is unique due to its transient characteristics: the plasma switches between non-thermal state (when EUV power is ON at the beginning of the pulse) and thermal state (end of the pulse at ∼20 μs). It is shown that although electron drag force acting on nm size particles in hydrogen plasma is negligible compared to the ion drag force at the beginning of the pulse, however it can be dominant at the end of the pulse and can play important role in particle transport leading to defectivity issues for semiconductor chip production technologies.

We present limits on spin-independent dark matter-nucleon interactions using a $10.6$ $\mathrm{g}$ Si athermal phonon detector with a baseline energy resolution of $\sigma_E=3.86 \pm 0.04$ $(\mathrm{stat.})^{+0.19}_{-0.00}$ $(\mathrm{syst.})$ $\mathrm{eV}$. This exclusion analysis sets the most stringent dark matter-nucleon scattering cross-section limits achieved by a cryogenic detector for dark matter particle masses from $93$ to $140$ $\mathrm{MeV}/c^2$, with a raw exposure of $9.9$ $\mathrm{g}\cdot\mathrm{d}$ acquired at an above-ground facility. This work illustrates the scientific potential of detectors with athermal phonon sensors with eV-scale energy resolution for future dark matter searches., Comment: 7 pages, 4 figures, this version includes ancillary files from official data release

Arbori -Horticulture: As Known in the Puranas

An Attempt to Neutralize the Space - charge of a hot Filament by Fast Positive Ions of Mercury Part I

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.

The detail microstructures of sintered natural magnesite with addition of titania, zirconia and ilmenite mineralisers were studied using scanning electron microscopy (SEM) with special emphasis on energy dispersive X-ray analyses (EDXA). The study was directed towards the determination of secondary phase composition in sintered magnesite with different mineraliser addition. In order to evaluate the secondary phases with addition of transition metal oxides, keeping titania (TiO2) as a reference mineraliser, a natural analog of titania containing iron i.e., Ilmenite (Fe2O3 · TiO2) and pure Zirconia (ZrO2) were added to magnesite which was then sintered up to 1700 °C. The relative behaviour of these pure and mixed oxide mineralisers during the sintering of magnesite has been evaluated with respect to their microstructure and secondary phase composition. The present paper showed that titania addition to natural magnesites resulted in the formation of calcium titanate in the secondary phase upon sintering. Zirconia, on the other hand, did not show any reaction product in the secondary phase. The addition of titania in the form of mixed oxide, ilmenite, also gave rise to calcium titanate formation, providing a similar microstructure, specially with reference to spatial distribution of phases in the secondary phase.

An analysis of nonlinear transverse shear wave has been carried out on non-Newtonian viscoelastic liquid using generalized hydrodynamic(GH) model. The nonlinear viscoelastic behavior is introduced through velocity shear dependence of viscosity coefficient by well known Carreau -Bird model. The dynamical feature of this shear wave leads to the celebrated Fermi-Pasta-Ulam (FPU) problem. Numerical solution has been obtained which shows that initial periodic solutions reoccur after passing through several patterns of periodic waves. A possible explanation for this periodic solution is given by constructing modified Korteweg de Vries (mKdV) equation. This model has application from laboratory to astrophysical plasmas as well as biological systems., 5 pages, 2 figures

Alumina-silicon carbide-carbon based resin bonded bricks have been finding increasing applications in the field of hot metal pretreatment process in torpedo ladle worldwide. In the pretreatment process in the steel ladles, refractories are subjected to very stringent demand of performance. This process helps in the production of quality steel and is the most preferred process.The alumina-silicon carbide-carbon based refractories are suitable for the torpedo ladle as they have the best slag penetration resistance and are thus suitable for slag zone and bottom impact zone of steel ladle. A complete study of various aspects of properties that affects the brick application has been enumerated in this paper.

The purpose of this study was to prepare activated carbon from an agricultural solid waste and assess its effectiveness in adsorptive removal of lead from aqueous solution. Activated carbon was prepared from coconut coir and its characteristics were compared with that of a commercial bituminous coal-based activated carbon. The coconut coir activated carbon possessed higher surface and micropore areas, micropore volume and average pore diameter, and well developed meso- and micropores. Adsorption of lead from aqueous solution by the coconut coir activated carbon was examined. Batch adsorption test showed that extent of adsorption was dependent on lead concentration, contact time, pH and activated carbon dose. Adsorption was low at acidic pH and increased up to pH 5, with marginal increase up to pH 6. Equilibrium adsorption was attained in 2.5 h. Lead adsorption followed pseudo-second order kinetics. Equilibrium lead adsorption data for the coconut coir activated carbon and commercial activated carbon were described by the Langmuir and Freundlich isotherm models. Coconut coir activated carbon showed higher lead adsorption capacity [7.75 (Langmuir) and 3.63 (Freundlich)] compared with the commercial activated carbon [7.55 (Langmuir) and 1.87 (Freundlich)]. Coconut coir activated carbon is a suitable substitute for commercial activated carbon in the adsorptive removal of lead from water.

The sintering and grain growth characteristics of natural cryptocrystalline magnesite from Salem, India, have been compared to samples that were bio-leached to reduce the silica content. Pressed compacts with the above magnesites without titania and with addition between 0.05 and 0.5 wt% of the original magnesite have been fired between 1450° and 1700°C with one to four hours soaking. The resultant compacts have been evaluated for their sintering behaviour and grain growth using optical microscopy and scanning electron microsocpy. Results show that the natural magnesite after bio-leaching of silica contained a high degree of direct bonding with low liquid phase content compared to the parent magnesite. A virtual absence of porosity and significant grain growth due to bio-leaching is observed. The presence of titania enhances the sintering at lower temperature and provides faster grain growth. Microstructure of samples are discussed in detail.

Paget's disease of bone is a rare disorder in India. Patients are usually asymptomatic and incidental radiological investigation invariably clinches the diagnosis. Increased alkaline phosphatase, X-ray, CT scan and scintiscan of bone can be done to confirm the diagnosis. Here we report a case of an 85-yr-old lady who had bilateral hearing loss for last 10 yrs, was admitted incidentally for some other complaints and on investigation diagnosed to have advanced Paget's disease of bone.

Cell lines selected in multiple steps for increasing resistance to hydroxyurea have been shown to have corresponding increases in ribonucleotide reductase activity. We have isolated a number of cDNA clones from a cDNA library constructed from a highly hydroxyurea-resistant hamster cell line, 600H, in which the activity of ribonucleotide reductase is elevated more than 80-fold. These clones correspond to genomic DNA sequences amplified in the 600H cell line compared with the V79 parental line. One of these cDNA clones, termed P5, codes for a 50 kDa protein detected by in vitro translation of poly(A)+ RNA isolated by hybridization/selection. The cDNA sequence contains a single open reading frame of 1317 nucleotides which encodes a polypeptide of 439 amino acids. The amino acid sequence deduced from the cDNA insert contains two copies of the 11-amino-acid sequence Val-Glu-Phe-Tyr-Ala-Pro-Trp-Cys-Gly-His-Cys. Duplicate copies of this sequence also occur in the active site of rat and human protein disulphide isomerase (also known as the beta-subunit of human prolyl 4-hydroxylase, tri-iodothyronine-binding protein) and in Form I phosphoinositide-specific phospholipase C, indicating that P5 falls into this newly defined superfamily of proteins. Genomic sequences similar to the cDNA clone are amplified 10-20-fold in hamster cells selected for resistance to increasing concentrations of hydroxyurea, a phenomenon observed earlier with cDNA clones for the M2 subunit of ribonucleotide reductase and ornithine decarboxylase. RNA blots probed with P5 cDNA show two poly(A)+ RNA species which are elevated in hydroxyurea-resistant cells.

The sintering and grain growth of natural Indian magnesite as a function of added titania have been studied in the range 0.05 to 0.50wt% TiO2 with respect to the natural magnesite. Grain sizes in fired compacts have been measured with the aid of an optical microscope on thin and polished sections. The activation energy for grain growth in magnesites with and without added titania has been calculated from the increase in average grain diameter as a function of firing temperature and time. A higher activation energy of 607 kJ/mol has been observed in the case of natural cryptocrystalline magnesite from Salem with 0.20 to 0.50wt% titania addition when compared to the activation energy of 293 kJ/mol in natural coarse crystalline magnesite from Almora with 0.50wt% added titania in the original magnesite. The higher activation energy is attributed to change in the mechanism of sintering due to the addition of titania.

The extent of protein N-glycosylation in Leishmania mexicana amazonensis has been proposed to be a factor in the virulence of the parasite. The N-linked oligosaccharides of gp63, the major surface glycoprotein of L. mexicana amazonensis, were characterized after their release by hydrazinolysis, re-N-acetylation, and reduction with NaB3H4. High voltage paper electrophoresis of the reduced oligosaccharides revealed only neutral species. Gel-permeation chromatography on Bio-Gel P-4 yielded four fractions, and the oligosaccharides present were structurally characterized by sequential exoglycosidase digestion, fragmentation by acetolysis, and methylation analysis. Four major structures were found and were biantennary oligomannose type with compositions of Glc1Man6GlcNAc2 (La), Man6GlcNAc2 (Lb), Man5GlcNAc2 (Lc), and Man4GlcNAc2 (Ld). The largest oligosaccharide (La) was shown to contain a terminal glucopyranosyl residue on the alpha (1----3) arm. The biantennary oligomannose structures (Lb and Lc) and the glucosylated structure Glc1Man6GlcNAc2 (La) have not previously been reported as a component of a mature glycoprotein from any source.

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.

The pathogens like Trichomonas vaginalis (4.5%), N gonorrhoeae (2.7%) and C albicans (6.7%) were exclusively present in leucorrhoea. The other potential agents with their respective percentages in normal women and cases of leucorrhoea were U urealyticum (21.2% and 50.2%), actinomyces (29.7% and 41.6%), Chlamydia trachomatis (17% and 48.8%), candida-like organisms (CLO) (1.2% and 9.5%) and non-group B streptococci (4.2% and 16.7%). The percentages of urethral syndrome (65.8%), vaginal irritation (63.4%), sore vulva (17%), cervicitis (13.4%), cervical erosion (11%) of the STD clinic were more than those of gynaecological cases. The latter group more often revealed infertility (15.8%) and pelvic inflammatory disease (13.6%). The exclusive isolation rate of N gonorrhoeae (7.3%) and prevalence of G vaginalis (19.5%) and Trichomonas vaginalis (8.5%) in the STD clinic were notable. The cases of gynaecological clinic more commonly showed C albicans (8%) and CLO (13.6%). Significant differences pertaining to U urealyticum (leucorrhoea and inapparent group p0.01; leucorrhoea and normal cases p0.01), M hominis (leucorrhoea and inapparent group p0.05; leucorrhoea and normal cases p0.01), Chlamydia trachomatis (leucorrhoea and normal cases p0.01) and also actinomyces (leucorrhoea and normal cases p0.01; inapparent and normal cases p0.05) were recorded. There was conspicuous association of U urealyticum, M hominis, G vaginalis, Chlamydia trachomatis, CLO and actinomyces with leucorrhoea. An almost exclusive presence of Staph aureus, Esch coli and Klebsiella in cases of leucorrhoea appeared meaningful.

To study the pharmacokinetics of theophylline and its correlations to pharmacodynamic effects in apnea of prematurity in small for gestational age babies.Prospective case control study.Level III Neonatal Intensive Care Unit.Ten small for gestational age (SGA) babies and 10 gestation matched appropriate for gestational age (AGA) babies with recurrent apnea of prematurity.All babies were investigated to exclude secondary causes of apnea. 5 mg/kg of aminophylline loading dose followed by 2 mg/kg as maintenance dose every 8 hourly intravenously was used. The trough and peak levels of theophylline were assessed on different days of therapy. Clinical monitoring was done for the efficacy and toxicity of the drug. Analysis was done using unpaired Student's 't' test and the correlation between plasma theophylline levels of different days was performed by using ANOVA.The therapeutic drug levels were achieved within 24 hours in all babies. The SGA babies showed 25% higher drug levels as compared to AGA babies. The mean trough plasma theophylline levels ranged from 8.15 +/- 1.59 to 12.37 +/- 1.54 micrograms/ml in SGA babies while in AGA babies they ranged from 6.26 +/- 1.93 to 9.96 +/- 1.96 micrograms/ml in first 8 days of therapy. The mean peak levels in SGA babies ranged from 11.91 +/- 1.84 to 17.13 +/- 1.63 micrograms/ml and in AGA babies ranged from 8.17 +/- 1.84 to 13.02 +/- 1.48 micrograms/ml. Twenty per cent SGA and AGA babies each developed clinical toxicity though toxic drug levels were found in 50% SGA and 30% AGA babies.There is a need to modify dosage schedule for these babies.

The prevalence of certain characteristics of genital discharge like (a) watery variety in sexually transmitted disease (STD) clinic 34% and in gynaecology clinic 26.6%, (b) fishy odour in STD clinic 29.2% and in gynaecology clinic 12.2% and (c) pH4.5 in STD clinic 53.6% and in gynaecology clinic 43% was notable. On the other hand, occurrence of "clue cells" (in STD clinic 41.4% and in gynaecology clinic 39.5%) did not show difference in the aforesaid clinics. The preponderance of watery discharge in the STD clinic appears to be related to G vaginalis (in STD clinic 26.8% and in gynaecology clinic 9.3%). It is intriguing to note that G vaginalis was isolated from leucorrhoea (in STD clinic 19.5% and in gynaecology clinic 9.3%) and inapparent (in 10%) cases and normal (in 4.2%) cases. Single infection with G vaginalis in one particular case had profuse watery discharge, pH4.5 and there was occurrence of "clue cells". Likewise, in multiple infections revealing G vaginalis (29 cases) as one of the potential agents, 78.5% had profuse, 53.8% watery discharge of which 53.5% had "clue cells" and 81% had pH4.5. In mixed type of infections, the U urealyticum (53.8%) and M hominis (30.6%) were conspicuous in bacterial vaginosis. Cervicitis, erosion cervix or urethral syndrome were unrelated to G vaginalis. All cases of G vaginalis infection responded to metronidazole with remission of leucorrhoea in 25.9% cases.

A retrospective study of lumps in the breast sent for histopathological examination in Calcutta National Medical College for a period of last 10 years was done. It was found that 2062 cases (6.82%) of histopathological examination of breast lump were studied out of a total 30208 specimens during that period. There were 1528 cases from benign breast lesions and 504 cases from the malignant breast lesions. The most common lesion found histologically was fibro-adenoma in 950 cases. Others included 150 cases of inflammatory breast diseases of which 36 cases were diagnosed as tuberculosis, 386 cases as fibrocystic disease and 42 cases as other benign neoplastic diseases. Out of 504 malignant cases 456 had carcinoma and 48 had sarcoma. Only 30 cases of male breast lesions were sent of which only a single case of infiltrating duct carcinoma was found, 28 cases had gynaecomastia and one case showed the evidence of fibrocystic disease.

Value of abnormal findings on 11 functional and behavioral items were studied for identification of serious illness, presence of bacteremia and prediction of the outcome (recovery or death) in infants upto 2 months of age. All the items were graded on a 3 point scale (0, 1 and 2) in the ascending order of severity. A total of 116 infants who were being evaluated for suspected sepsis were enrolled. The assessment was completed before detailed history and physical examination. Significant associations were observed between presence of serious illness and six items by lambda2-test and/or Pearson's correlation and multiple stepwise regression analysis. These were decreased activity, abnormal quality of cry, presence of pallor, fast breathing, decreased consolability, and consciousness level. The sensitivity of six item model was90% and negative predictive value95%. The negative predictive value of several individual items was also above 90%. Consciousness level was the most important predictor of the outcome followed by poor feeding, hydration, color, consolability and abnormal expression (combined multiple R = 0.51). A total score of 7 or more on above six items had a sensitivity of 80%, and negative predictive value of 97% for death. In conclusion, behavior and functional responses (as mentioned above) were fairly useful in predicting the outcome and/or the severity of the illness. These items may be combined to develop a scale to help in therapeutic decision making.

The study describes a new wet chemical technique, termed ANM, for the isolation of secondary phases in magnesite processed at a temperature of 1650 degrees C. The major MgO (periclase) phase in processed magnesite was preferentially extracted as ammonium nitrate magnesium double salt by ammonium nitrate in ethanol medium. The residues containing enriched secondary phases were identified by XRD.

The fibroblast growth factor receptor 1 (flg) contains eight acidic amino acids between the first and second immunoglobulin domain. This report examines the role of the acidic domain in the interaction of the flg receptor with its ligands. We observed a marked inhibition of binding of bFGF to the receptor when the acidic domain was completely deleted, but mutants with two and four amino acids deleted (flgΔ2 and flgΔ4, respectively) still bound the ligand. After addition of a bifunctional cross-linking reagent, cross-linked complexes (between bFGF and receptor) with the expected size were observed in cells expressing mutants lacking two or four acidic residues, but not in cells expressing mutants lacking six or eight acidic residues. Immunoprecipitation with anti-flg antibody followed by electrophoresis produced a band of 90 Kd in tunicamycin-treated cells expressing the mutant as well as the wild-type receptors, indicating that the inhibition of binding was not due to defective expression of the protein. The ability of flgΔ8 to mediate a mitogenic response to FGFs was also greatly reduced when this mutated receptor was expressed in receptor-negative cells. The effect of replacing the acidic amino acids with lysine residues was also studied. Binding of bFGF to cells transfected with a plasmid encoding a mutated protein with four amino acid substitutions was totally inhibited, but an eight amino acid substitution did not alter ligand binding to the receptor. In this case the mutation with four amino acids substitution caused a drastic impairment of protein expression. Thus the acidic domain of the FGFR-1 plays an essential role in receptor function, either because it is important for a stable protein configuration or for ligand-receptor interaction. © 1993 Wiley-Liss, Inc.

Ribonucleotide reductase activity is markedly elevated in cell lines selected for resistance to hydroxyurea, a cytotoxic drug known specifically to inhibit ribonucleotide reductase. From a cDNA library constructed from a highly hydroxyurea-resistant hamster lung cell line, 600H in which the activity is elevated more than 80-fold, we have isolated a full length cDNA for the small subunit of the reductase. The cDNA is 3.48 kb long with an open reading frame of 1158 nucleotides and a long 3′ flanking region of 2169 nucleotides from the termination codon. The derived polypeptide sequence is closely similar to the small subunit of the mouse, differing from it in 20 amino acid positions. Most of these replacements occur in the N-terminal segment of the protein. The hamster subunit does not contain 4 amino acid residues found in the mouse small subunit near the C-terminal end. RNA blots probed with the cDNA show two poly(A) + RNA species which are elevated in hydroxyurea-resistant cells.

The extent of protein N-glycosylation in Leishmania mexicana amazonensis has been proposed to be a factor in the virulence of the parasite. The N-linked oligosaccharides of gp63, the major surface glycoprotein of L. mexicana amazonensis, were characterized after their release by hydrazinolysis, re-N-acetylation, and reduction with NaB3H4. High voltage paper electrophoresis of the reduced oligosaccharides revealed only neutral species. Gel-permeation chromatography on Bio-Gel P-4 yielded four fractions, and the oligosaccharides present were structurally characterized by sequential exoglycosidase digestion, fragmentation by acetolysis, and methylation analysis. Four major structures were found and were biantennary oligomannose type with compositions of Glc1Man6GlcNAc2 (La), Man6GlcNAc2 (Lb), Man5GlcNAc2 (Lc), and Man4GlcNAc2 (Ld). The largest oligosaccharide (La) was shown to contain a terminal glucopyranosyl residue on the alpha (1----3) arm. The biantennary oligomannose structures (Lb and Lc) and the glucosylated structure Glc1Man6GlcNAc2 (La) have not previously been reported as a component of a mature glycoprotein from any source.

In both species of zebra, breeding males had higher urinary androgen concentrations (ng androgens/mg Cr) than did non-breeding bachelor males (30.0 +/- 5.0 (N = 9) versus 11.4 +/- 2.8, (N = 7) in the plains zebra; 19.0 +/- 2.2 (N = 17) versus 10.7 +/- 1.2 (N = 14) in the Grevy's zebra). In the more stable family structure of the plains zebra (single male non-territorial groups) variations in androgen concentrations could not be ascribed to any measured variable. In the Grevy's zebra, androgen values were significantly lower in samples taken from territorial (breeding) males which had temporarily abandoned their territories (N = 4) and the urinary androgen concentration for a male on his territory was negatively correlated with the time since females last visited the territory.

To study the interaction of splicing factors with the simian virus 40 early-region pre-RNA, which can be alternatively spliced to produce large T and small t mRNAs, we used an in vitro RNase protection assay that defines the 5' boundaries of factor-RNA interactions. Protection products reflecting factor interactions with the large T and small t 5' splice sites and with the multiple lariat branch site region were characterized. All protection products were detected very early in the splicing reaction, before the appearance of spliced RNAs. However, protection of the large T 5' splice site was detected well before small t 5' splice site and branch site protection products, which appeared simultaneously. Oligonucleotide-targeted degradation of small nuclear RNAs (snRNAs) revealed that protection of the branch site region, which occurred at multiple sites, required intact U2 snRNA and was enhanced by U1 snRNA, while protection of the large T and small t 5' splice sites required both U1 and U2 snRNAs. Analysis of several pre-RNAs containing mutations in the branch site region suggests that factor interactions involving the multiple copies of the branch site consensus determine the selection of branch points, which is an important factor in the selection of alternative splicing pathways.

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.

In the analysis of centre-fed cylindrical dipole antennas with displaced feed points, a sinusoidal or King's three-term distribution has been assumed to hold good. This, however, is not accurate. The paper presents an analysis for the distribution of current in center-fed cylindrical antenna systems with feed points displaced arbitrarily, the cases of axial and transverse displacement of points follow as special cases.The problem is treated as a boundary value problem, Hallen's integral equation is formulated and its solution is obtained using King's Kernel inspection technique, which directly gives the distribution of current along the antenna.The expression obtained is qualitatively similar to King's three-term formula but the value of individual coefficients occurring in the expression are different. Thus a first order correction to the King's formula necessary for taking into account the effect of displacement of the feed points is deduced.