An HPLC method for simultaneous determination of residual benomyl and MBC on apple foliage without cleanup

A simple High Performance Liquid Chromatograph (HPLC) method has been developed to identify benamyl (methyl 1- (butylcarbamoyl)-2-benzimidazole carbamate) and MBC (methyl 2-benzimidazole carbamat~ residues on apple leaves without cleanup. Sample leaves are freeze dried in a Mason jar and residues are then extracted by tumbling them in chloroform containing 5,000 microgram per milliliter of n-propyl isocyanate (PIC) at 10 C. To the extract, n-butyl isocyanate (BIC) was added at 5,000 microgram per milliliter and 20 microliter of this mixture injected onto the HPLC system. Separation is accomplished by the use of a Brownlee LiChrosorb silica gel column with a guard column and' operated with a mixed mobile phase consisting of chloroform and hexane (4:1) saturated with water. MBC, a degradation product of benomyl is identified if present as methyl l-(npropyl carbamoyl)-2-benzimidazole carbamate (MBC-n-PIC). Both benomyl and MBC-n-PIC can be detected with aKUltraviolet (UV) detector (280nm) at a concentration as low as 0.2 microgram per milliliter in apple leaves. The fate of benomyl on apple foliage after spray application of benomyl (Ben late 50 per cent wettable powder) was investigated by the method thus described. Benomyl quickly dissipated during the first 3-7 days, but the dissipatio'n sltowed down thereafter. In contrast, the concentration of MBC in leaves gradually increased after repeated applications of Benlate.

Simultaneous extraction of order parameters and orientational distribution fuctions from 31[superscript]P NMR spectra of magnetically partially oriented phospholipid bilayers

Order parameter profiles extracted from the NMR spectra of model membranes are a valuable source of information about their structure and molecular motions. To al1alyze powder spectra the de-Pake-ing (numerical deconvolution) ~echnique can be used, but it assumes a random (spherical) dist.ribution of orientations in the sample. Multilamellar vesicles are known to deform and orient in the strong magnetic fields of NMR magnets, producing non-spherical orientation distributions. A recently developed technique for simultaneously extracting the anisotropies of the system as well as the orientation distributions is applied to the analysis of partially magnetically oriented 31p NMR spectra of phospholipids. A mixture of synthetic lipids, POPE and POPG, is analyzed to measure distortion of multilamellar vesicles in a magnetic field. In the analysis three models describing the shape of the distorted vesicles are examined. Ellipsoids of rotation with a semiaxis ratio of about 1.14 are found to provide a good approximation of the shape of the distorted vesicles. This is in reasonable agreement with published experimental work. All three models yield clearly non-spherical orientational distributions, as well as a precise measure of the anisotropy of the chemical shift. Noise in the experimental data prevented the analysis from concluding which of the three models is the best approximation. A discretization scheme for finding stability in the algorithm is outlined

Explorations and comparisons of actual, ideal, and ought forgiveness definitions : a Q-methodological study /

Numerous definitions of forgiveness have been proposed in the literature (e.g.. North, 1987; Enright, Freedman & Rique, 1998), most ofwhich are based on religious or philosophical notions, rather than on empirical evidence. Definitions employed by researchers have typically set very high standards for forgiveness. This research was designed to investigate the possibility that these definitions describe an ideal of forgiveness and may not reflect laypersons' beliefe and experiences. Using Higgins' Self-Discrepancy Theory as a fiamework, three types of forgiveness beliefs were investigated: actual, ideal, and ought Q-methodology (which permits intensive study ofphenomena in small samples) was employed to examine and compare participants' beliefs about forgiveness across these domains. Thirty participants (20 women), 25 to 78 years of age, were recruited firom the community. They were asked to sort a set of66 statements about forgiveness according to their level of agreement with each statement This process was repeated three times, with the goal of modelling participants' actual experiences, their ideals, and how they believed forgiveness ought to be. Three perspectives on forgiveness emerged across the domains: forgiveness as motivated by religious beliefs, reconciliation-focussed forgiveness, and conflicted forgiveness. These perspectives indicated that, for many participants, the definitions presented in the literature may coincide with their beliefs about how forgiveness would ideally be and should be, as well as with their experiences of forgiveness; however, a large number of participants' experiences of, and beliefs about, forgiveness do not conform to the standards set out in the literature, and to exclude these participants' experiences and beliefs would mean overlooking what forgiveness means to a large portion of people. Results of this study indicate that researchers need to keep an open mind about what forgiveness may mean to their participants.

Problem solving and computer-assisted instruction in science education : analysis of research findings and the research process /

The quantitative component of this study examined the effect of computerassisted instruction (CAI) on science problem-solving performance, as well as the significance of logical reasoning ability to this relationship. I had the dual role of researcher and teacher, as I conducted the study with 84 grade seven students to whom I simultaneously taught science on a rotary-basis. A two-treatment research design using this sample of convenience allowed for a comparison between the problem-solving performance of a CAI treatment group (n = 46) versus a laboratory-based control group (n = 38). Science problem-solving performance was measured by a pretest and posttest that I developed for this study. The validity of these tests was addressed through critical discussions with faculty members, colleagues, as well as through feedback gained in a pilot study. High reliability was revealed between the pretest and the posttest; in this way, students who tended to score high on the pretest also tended to score high on the posttest. Interrater reliability was found to be high for 30 randomly-selected test responses which were scored independently by two raters (i.e., myself and my faculty advisor). Results indicated that the form of computer-assisted instruction (CAI) used in this study did not significantly improve students' problem-solving performance. Logical reasoning ability was measured by an abbreviated version of the Group Assessment of Lx)gical Thinking (GALT). Logical reasoning ability was found to be correlated to problem-solving performance in that, students with high logical reasoning ability tended to do better on the problem-solving tests and vice versa. However, no significant difference was observed in problem-solving improvement, in the laboratory-based instruction group versus the CAI group, for students varying in level of logical reasoning ability.Insignificant trends were noted in results obtained from students of high logical reasoning ability, but require further study. It was acknowledged that conclusions drawn from the quantitative component of this study were limited, as further modifications of the tests were recommended, as well as the use of a larger sample size. The purpose of the qualitative component of the study was to provide a detailed description ofmy thesis research process as a Brock University Master of Education student. My research journal notes served as the data base for open coding analysis. This analysis revealed six main themes which best described my research experience: research interests, practical considerations, research design, research analysis, development of the problem-solving tests, and scoring scheme development. These important areas ofmy thesis research experience were recounted in the form of a personal narrative. It was noted that the research process was a form of problem solving in itself, as I made use of several problem-solving strategies to achieve desired thesis outcomes.

Armor coats, inverse grading, and streambed scour in selected streams of Southern Ontario and Western New York /

Surface size analyses of Twenty and Sixteen Mile Creeks, the Grand and Genesee Rivers and Cazenovia Creek show three distinct types of bed-surface sediment: 1) a "continuous" armor coat which has a mean size of -6.5 phi and coarser, 2) a "discontinuous" armor coat which has a mean size of approximately -6.0 phi and 3) a bed with no armor coat which has a mean surface size of -5.0 phi and finer. The continuous armor coat completely covers and protects the subsurface from the flow. The discontinuous armor coat is composed of intermittently-spaced surface clasts, which provide the subsurface with only limited protection from the flow. The bed with no armor coat allows complete exposure of the subsurface to the flow. The subsurface beneath the continuous armor coats of Twenty and Sixteen Mile Creeks is possibly modified by a "vertical winnowing" process when the armor coat is p«natrat«d. This process results in a welld «v«loped inversely graded sediment sequence.vertical winnowing is reduced beneath the discontinuous armor coats of the Grand and Genesee Rivers. The reduction of vertical winnowing results in a more poorly-developed inverse grading than that found in Twenty and sixteen Mile Creeks. The streambed of Cazenovia Creek normally is not armored resulting in a homogeneous subsurface which shows no modification by vertical winnowing. This streambed forms during waning or moderate flows, suggesting it does not represent the maximum competence of the stream. Each population of grains in the subsurface layers of Twenty and sixteen Mile Creeks has been modified by vertical winnowing and does not represent a mode of transport. Each population in the subsurface layers beneath a discontinuous armor coat may partially reflect a transport mode. These layers are still inversely graded suggesting that each population is affected to some degree by vertical winnowing. The populations for sediment beneath a surface which is not armored are probably indicative of transport modes because such sediment has not been modified by vertical winnowing. Bed photographs taken in each of the five streams before and after the 1982-83 snow-melt show that the probability of movement for the surface clasts is a function of grain size. The greatest probability of of clast movement and scour depth of this study were recorded on Cazenovia Creek in areas where no armor coat is present. The scour depth in the armored beds of Twenty and Sixteen Mile Creeks is related to the probability of movement for a given mean surface size.

The application of gas liquid chromatography to the simultaneous analysis of sugars and sugar phosphates in biological samples /|nby David J. LeBlanc. -- 260 St. Catharines [Ont. : s. n.],

A study was undertaken' to determine the applicability of gas liquid chromatography to the simultaneous analysis of sugars and sugar phosphates from biological samples. A new method of silylation involving dimethylsulfoxide, hexamethyldisilazane, trimethylchlorosilane and cyclohexane (1:0.2:0.1:1) which rapidly silylated sugars and sugar phosphates was developed. Subsequent chromatography on a 5% SE-52 column gave good resolution of the sugar and sugar phosphate samples. Sugar phosphates decomposed during chromatography and were lost at the 7 x 10-3 ~mole level. Acidic ethanol extraction of yeast samples revealed background contamination from the yeast sample, the culture medium and the silylation reagents which would further limit the level of detection obtainable with the glc for sugars in biological samples to the 3 x 10-4 ~mole level.