1,068 research outputs found

    Investigating texture six zero lepton mass matrices

    Full text link
    Texture six zero Fritzsch like as well as non Fritzsch like hermitian lepton mass matrices (144 combinations in all) have been investigated for both Majorana and Dirac neutrinos for their compatibility with the current neutrino oscillation data, keeping in mind the hierarchy of neutrino masses. All the combinations considered here for Majorana neutrino masses are ruled out by the existing data in the case of inverted hierarchy and degenerate scenario. For Majorana neutrinos with normal hierarchy, only 16 combinations can accommodate the experimental data. Assuming neutrinos to be Dirac particles, normal hierarchy, inverted hierarchy as well as degenerate neutrinos are ruled out for all combinations of texture 6 zero hermitian mass matrices.Comment: 14 pages, 2 figure

    Induction of pollen sterility in grapes (Vitis vinifera)

    Get PDF
    The morphology of the grape flower renders hand emasculation very tedious and hence hinders large scale hybridisation work. Chemical induction of male sterility which has been successfully achieved in some crops may likewise aid in grape breeding, if the method proves practicable. This paper deals with an experiment designed to achieve this object.Three varieties of grapes, Bhokri, Hussaini and Rosem-T-Lahore (all belonging to Vitis vinifera) were tested with three different chemicals, viz. maleic hydrazide, tri-iodobenzoic acid and FW-450, using various concentrations. In the first two varieties the dosages of maleic hydrazide 500 ppm, tri-iodobenzoic acid 400 ppm and FW-450 0.30% was found to induce complete pollen sterility. However, the third variety needed higher concentrations. In all cases two applications of the chemicals were necessary to induce comp1ete pollen sterility. In addition to inducing pollen sterility, FW-450 prevented anthesis and anther dehiscence. Considering the fruit set and seed set obtained in the male sterile flowers (induced by various chemicals) rby using good pollen, maleic hydrazide appears to be most promising. The chemical treatments did not influence seed germination. The most important factors with regard to the use of this method were  (1) the variety used, (2) the chemical applied, (3) the number of applications of the chemical and(4) the stage at which the chemical treatments are made. The implications of these results have been discussed

    Development of a heating reactor for a continuous flow-through application in urea measurement

    Get PDF
    In most biochemical analyses, a flow-through heating arrangement is needed to reduce the reaction time or maintain a constant temperature. A rectangular reactor is described that is constructed of aluminium, is hollow inside and is filled with silicone oil. The glass coil through which the solution flows is immersed in the silicone oil. The heater, a Peltier-effect heat pump, on one side and the temperature sensor on the other side of the reactor body are embedded for heating and temperature control. The brief performance evaluation of the reactor is discussed by measuring the absorbance of urea concentration at different temperatures

    Oxidative decolorization of methylene blue by leached sea-nodule residues generated by the reductionroasting ammoniacal leaching process

    Get PDF
    The leached residue, generated after selective extraction of Cu, Ni and Co by reductive-roasting ammoniacal leaching of sea nodules, was characterized by various physicochemical methods. The finely divided residue, containing mainly manganese carbonate/silicates and manganese(III,IV) (hydr)oxides along with iron oxides, showed a lower surface area (66.3 m2g− 1)than that of the parent sea nodule (130 m2g− 1). The catalytic efficiency of water-washed sea nodule residue (WSNR) was evaluated taking oxidative decolorization of methylene blue (MB) as the test reaction. The extent of decolorization was decreased with increase in pH but increased in the presence of H2O2 or NaCl. Decolorization of MB occurred in two consecutive steps; the rate constant of the first step was ∼ 10 times higher than that of the second step. The formation of a surface precursor complex between WSNR and MB at a rate-limiting step, followed by electron transfer from MB to the active metal centre of WSNR and release of product(s), was proposed as the ecolorization process

    Effect of Post-Harvest Treatment on Storage Quality in 'Umran' Ber Fruit

    Get PDF
    An experiment was conducted to study the effect of post-harvest sprays of CaCl2 (@ 0.5%, 1.0%&2.0%), Ca(NO3)2 (@ 0.5%, 1.0%&2.0%), GA3 (@ 20, 40 and 60 ppm) and Bavistin (0.1%) on storage quality of 'Umran' ber'. Fruits of uniform size were harvested at physiological maturity and treated with various chemicals. Treated fruits were placed in CFB boxes and placed in cold storage (3-5 °C and 85-95% RH). Stored fruits were evaluated at 10, 20 and 30 days from storage for palatability rating, TSS, acidity, Vitamin C and total sugars. After 30 days from storage, the highest palatability rating was recorded in GA3 (60 ppm) treated fruits, followed by CaCl2 (2.0%). Both TSS and Total sugars showed a similar trend of increase upto 20 days from storage, followed by a decrease. However, acidity and Vitamin C content of fruits decreased continuously with advancement of storage period. At the end of storage, maximum TSS, total acidity Vitamin C and total sugars were observed in GA3 (60 ppm) treated fruits, followed by CaCl2 (2.0%). Studies revealed that GA3 (60 ppm) treated ber fruits maintained very good quality at 20 days of cold storage

    A prospective randomized trial of FK506-based immunosuppression after renal transplantation

    Get PDF
    A group of 204 adult patients was entered into a prospective, randomized trial comparing FK506/pred-nisone with FK506/azathioprine/prednisone after renal transplantation between August 1, 1991 and October 11,1992. The purpose of the study was to see if the addition of azathioprine would reduce the incidence of rejection and improve graft survival. The recipient population was unselected, with 61 (30%) patients undergoing retransplantation, 37 (18%) having a panel-reactive antibody greater than 40%, and 33 (16%) over 60 years of age. The mean recipient age was 43.8±13.7 years (range 17.6-78). The mean donor age was 34.0±20.1 years (range 0.3-75); 13% of the cadaveric kidneys were from pediatric donors less than 3 years of age and were transplanted en bloc. The mean cold ischemia time was 31.4±8.4 hr. Living donors were the source of 13% of the kidneys. The mean follow-up was 22±4 months (range 12-29). Overall one-year actual patient survival was 94%. Overall one-year actual graft survival was 87%. Patients starting on double therapy had a one-year actual patient survival of 96% and a one-year actual graft survival of 92%. Patients starting on triple therapy had a one-year actual patient survival of 91% (P=ns compared with double therapy), and a one-year actual graft survival of 82% (P<0.02, compared with double therapy). Overall results with first cadaver transplants included a one-year actual patient survival of 94% and one-year actual graft survival of 88%, with no differences between double and triple therapy. The overall incidence of rejection was 48%, with 54% in the double therapy group and 41% in the triple therapy group (P<.07). The incidence of steroid-resistant rejection requiring antilymphocyte therapy (OKT3 or ATGAM) was 13%, and was not different between the double and triple therapy groups. The mean serum creatinine was 1.8±0.8 mg/dl. The mean BUN was 33±21 mg/dl, with no significant difference between the therapy groups. The mean serum cholesterol was 192 ±49 mg/dl. A total of 56% of the patients are off prednisone, and 35% of the patients are not taking any antihypertensive medications. Other complications included cytomegalovirus—14%; new-onset diabetes—16% (half of which was reversible); and posttransplant lymphoproliferative disorder—1%. There was a high incidence of crossover between the two groups, 27% of the patients in the double therapy group requiring the addition of azathioprine, and 45% of the patients in the triple therapy group requiring its discontinuation (usually tempoгагу). These results show that FK506 is an excellent immunosuppressive agent after renal transplantation and that azathioprine is not routinely effective as a third agent. A high quality of life resulted from the ability to use no (56%) or low-dose maintenance steroids. © 1995 by Williams and Wilkins

    Tacrolimus rescue therapy for renal allograft rejection - Five-year experience

    Get PDF
    Over the 5 year period from 7/14/1989 until 5/24/1994, we have attempted graft salvage with tacrolimus conversion in a total of 169 patients (median age 33 years, range 2-75 years) with ongoing rejection on baseline CsA immunosuppression after failure of high dose corticosteroids and/or antilymphocyte preparations to reverse rejection. The indications for conversion to tacrolimus were ongoing, biopsy confirmed rejection in all patients. The median interval to tacrolimus conversion was 2 months (range 2 days to 55 months; mean 4.3±2.6 months) after transplantation. All patients had failed high dose corticosteroid therapy and 144 (85%) of the 169 patients had received at least one course of an antilymphocyte preparation plus high dose corticosteroid therapy prior to conversion. Twenty-eight patients (17%) were dialysis-dependent at the time of conversion owing to the severity of rejection. With a mean follow-up of 30.0±2.4 months (median 36.5 months, range 12-62 months), 125 of 169 patients (74%) have been successfully rescued and still have functioning grafts with a mean serum creatinine (SCR) of 2.3±1.1 mg/dl. Of the 144 patients previously treated with antilymphocyte preparations, 117 (81%) were salvaged. Of the 28 patients on dialysis at the time of conversion to tacrolimus, 13 (46%) continue to have functioning grafts (mean SCR 2.15±0.37 mg/dl) at a mean follow-up of 37.3±16.7 months. In the 125 patients salvaged, prednisone doses have been lowered from 28.0±9.0 mg/d (median 32, range 4-60 mg/d) preconversion to 8.5±4.1 mg/d (median 12 mg/d, range 2.5-20 mg/d) postconversion. Twenty-eight patients (22.4%) are currently receiving no steroids. This 5 year experience demonstrates that tacrolimus has sustained efficacy as a rescue agent for ongoing renal allograft rejection. Based on these data, we recommend that tacrolimus be used as an alternative to the conventional drugs used for antirejection therapy in renal transplantation
    corecore