Preparation of hybrid AHO-POSS/polypropylene nanocomposite monofilaments by radiation induced grafting

The Allyl-heptaisobutyl-polyhedral Oligomeric Silsesquioxane (AHO-POSS) grafted polypropylene (PP) nanocomposite monofilaments were prepared by γ-ray irradiation induced grafting. The structure and properties of physically blended and γ-ray irradiated AHO-POSS/PP nanocomposite filaments were investigated by FTIR, wide-angle X-ray diffraction (WAXD), Thermo-gravimetric Analysis and mechanical property studies. Chemical bonding of AHO-POSS with PP after γ-ray irradiation was confirmed by FT-IR spectroscopy. Grafting resulted in change in mechanical and thermal properties and the extent of change was critically dependent on loading of AHO-POSS in PP and radiation dose level. In general, tensile strength decreased almost continuously with increase in radiation dose whereas thermal stability increased upto a radiation dose of 5 kGy and then decreased. The loss in tensile strength was caused due to chain scission, cross linking and loss in orientation.     

POSS/polypropylene hybrid nanocomposite monofilaments by reactive extrusion

The Allyl-heptaisobutyl-polyhedral oligomeric silsesquioxane (AHO-POSS) grafted polypropylene (PP) was prepared by reactive extrusion and by physical blending routes. The structure and properties of physically blended and reactively blended POSS/PP nanocomposites were investigated by FTIR, wide-angle X-ray diffraction (WAXD), differential scanning calorimetry (DSC), thermogravimetric analysis, SEM, spherutlic growth and mechanical properties studies. Chemical bonding of POSS with PP in reactive extrusion was confirmed by FT-IR spectroscopy. DSC and TGA studies showed that the thermal stability of AHO-POSS/PP nanocomposite prepared by reactive extrusion improved significantly as compared to only physically blended nanocomposites. WAXD studies showed decrease in crystallinity of the AHO-POSS/PP nanocomposites prepared by reactive extrusion. SEM studies showed aggregation tendency in case of physically blended AHO-POSS/PP nanocomposites. Spherulite growth studies show reactive blending retards spherulite growth in PP polymer.     

Biochemical and histochemical traits: a promising way to screen resistance against spot blotch (Bipolaris sorokiniana) of wheat

Spot blotch caused by Bipolaris sorokiniana is a serious disease of wheat in warmer and humid regions of the world. Three blighting components, area under disease progress curve (AUDPC), disease severity (DS) and lesion size along with four biochemical and histochemical factors viz., total phenol content (TPC), chlorophyll content (CHC), phenylalanine ammonia-lyase (PAL) activity and lignin deposition were studied in a recombinant inbred lines (RILs) population involving parents “Sonalika” (susceptible) and “Yangmai 6” (resistant). The objective was to identify one or more robust and reliable tools of resistance, physical, biochemical or histochemical, to facilitate selection against spot blotch. The DS, AUDPC and lesion size were higher in the susceptible parent and RILs compared to the resistant. The mean TPC (246 mg Gallic acid g^?1 fresh weight) of the most resistant RIL was significantly higher than the most susceptible (181.5 mg Gallic acid g^?1 fresh weight) at 48 h after inoculation (hai). The mean SPAD value for CHC varied between 48.8 in the most resistant RILs to 8.8 in the most susceptible, while the mean PAL varied between 928.4 and 96.0 μmoles Cinnamic acid mg^-1 fresh weight at 48 hai in resistant and susceptible RILs, respectively. Likewise, lignin deposition was significantly higher in resistant RILs compared to the susceptible. The biochemical and histochemical parameters were significantly correlated with resistance and appeared robust for facilitating screening of breeding material and for increased precision in phenotyping against spot blotch.     

Farmers' knowledge,attitudes and practices of rice crop and pest management at Ifugao Rice Terraces,Philippines

A survey of 150 rice farmers in three municipalities of the Ifugao Rice Terraces, Philippines, carried out in June 1998, aimed to assess the farmers' knowledge, attitudes, and practices of rice crop and pest management. The survey revealed that: 54% of the farmers fall within a narrow age range (31-50 years), the majority having 11-30 years of rice farming experience; they are of average literacy; and they have large households. Non-farm activity such as woodcarving was the most common source of additional income. The majority of farmers planted a single crop of rice per year and followed traditional cultivation practices. Major rice crop production constraints were drought due to the El Nino phenomenon and insufficient irrigation infrastructure. Zinc deficiency was widespread. Major, non-insect pests known to farmers were earthworms, rats, golden apple snails, and house sparrows. These pests damage either the rice plant or the terrace wall. Earthworm damage to the terrace wall is most obvious. Farmers had very little exposure to integrated pest management and new rice technologies.     

Introduction of bulls at different days postpartum on resumption of ovarian cycling activity in primiparous beef cows

The objective of this study was to evaluate postpartum resumption of ovulatory cycles among primiparous, suckled beef cows that were exposed continuously to mature bulls beginning at various intervals after calving. We sought to determine whether cumulative distributions of proportions of cows resuming ovarian cycles and interval from the start of bull exposure to resumption of ovarian cycling activity differed among cows exposed continuously (BE) or not exposed (NE) to bulls beginning on d 15, 35, or 55 after calving. Angus x Hereford cows (n = 56) were assigned randomly to one of six treatments in a 2 (exposure type) x 3 (day exposed postpartum) factorial arrangement. Blood samples were collected from each cow starting on d -1, and every third day until the end of experiment. An increase in baseline progesterone concentrations that exceeded 1.0 ng/mL in three consecutive samples was used as evidence of resumption of ovarian cycling activity. More (P < 0.05) BE cows resumed cycling activity by the end of the experiment than NE cows. Proportions of cows resuming cycling activity did not differ (P = 0.30) among cows exposed to bulls on d 15, 35, or 55 postpartum. Proportions of BE cows that were exposed to bulls on d 15, 35, or 55 were greater for each 10-d interval (P < 0.05) than those for NE cows during the first 40 d after exposure. More (P < 0.05) BE cows exposed to bulls on d 55 resumed cycling activity by 30 d after exposure than BE cows exposed to bulls on either d 15 or 35. Interval from calving to resumption of cycling activity was decreased (P < 0.05) by the presence of bulls. Day of exposure did not affect (P = 0.21) interval from calving to resumption of cycling activity; however, interval from day of bull exposure to resumption of cycling activity decreased (P < 0.05) linearly as day of exposure to bulls after calving increased. We conclude that exposing primiparous beef cows to bulls decreased the postpartum anovulatory interval and increased the proportion of cows that exhibit resumption of ovarian cycling activity, independent of day of bull exposure. Furthermore, cows exposed to bulls at progressively later intervals postpartum seemed to respond more rapidly to the biostimulatory effect of bulls than when they were exposed earlier in the postpartum anestrous period.     

Organic pesticides. XV. Synthesis and insecticidal activity of some compounds containing phosphorus and fluorine

Forty new organofluorine compounds, containing phosphorus, have been synthesised as potential pesticides. The compounds include esters of O,O-dialkyl phosphoramidic acids of the type (RO)₂P(O)NHAr; thioesters of O,O-dialkyl thiophosphoramidic acids of the type (RO)₂P(S)NHAr; esters of O,O-dialkyl phosphonic acid of the type (RO)₂P(O)Ar and esters of O,O-dialkyl thiophosphonic acid (RO)₂P(S)OAr. All the compounds have been screened for their insecticidal activity against adult cockroaches (Periplanata americana) and a few show appreciable activity.     

Prediction ofPuccinia Graminis f. sp.Tritici on wheat in india by trapping the uredospores in rain samples

Five years of trapping uredospores in rain samples resulted in their detection on an average of 22 days earlier than in the impaction traps, and 36 days before the first appearance of stem rust on a susceptible cultivar. On many occasions the presence of uredospores in rain samples was not followed by the occurrence of wheat rust in the field.     

Gas chromatographic determination of histapyrrodine hydrochloride in pharmaceutical preparations

A simple gas chromatographic method is described for the determination of histapyrrodine HCl in marketed formulations. Chlorpheniramine maleate is used as the internal standard. The amount of histapyrrodine HCl found by the proposed method averaged 19.91 mg/tablet, compared with the label claim of 20 mg/tablet. The method was statistically evaluated for accuracy and precision.