The near ultraviolet absorption spectrum of phosgene /

The near ultraviolet absorption of phosgene has been assigned to a * 1 1 ~.--n, A;-- Al electronic transition from vapour phase spectra recorded under conditions of high resolution and low_t~mperature. Progressions in Vi, v2' V3' V4 and V4 ha\1e been identified in the spectrum and have been analyzed in terms of vibronic transitions between a planar ground and a nonplanar excited state. A ba~rier height of 3170 cm~l:and a nona planar equilibrium angle of 32.5 were calculated for the upper state from a fit of the energy levels of a Lorentzian-guadratic potential func- ~ion to the observed levels of V 4 . ' ~he false ori- 3in, 41 0 , of the spectrum has been assigned to the band at 33,631 cm -1 . An oscillator strength of -3 1 . 1 f = 1. a x 10 has been obtained for the A - A 2 1 transition.

The satellite band patterns in the near ultraviolet absorption spectra of isotopic compounds of acetaldehyde

The 3700 A - 3000 A absorption spectra of CH3CHO and its isotopic compounds such as CH3CDO, CD3CHO and CD3CDO were studied in the gas phase at room temperature and low temperatures. The low resolution spectra of the compounds were recorded by a 1.5 m Baush and Lomb grating spectrograph. The high resolution spectra were recorded by a Ebert spectrograph with the Echelle grating and the holographic grating separately. The multiple reflection cells were used to achieve the long path length. The pressure-path length used for the absorption spectrum of CH 3CHO was up to 100 mm Hg )( 91 . 43mo The emission spectrum and the excitation spectrum of CH3CHO were also recorded in this research. The calculated satellite band patterns \vhich were ob-tailied by the method of Lewis were used to compare with the observed near UV absorption spectrum of acetaldehyde. These calculated satellite band patterns belonged to two cases: namely, the barriers-in-phase case and the barriers- out-of-phase case. Each of the calculated patterns corresponded to a stable conformation of acetaldehyde in the excited state . The comparisons showed that the patterns in the observed absorption spectra corresponded to the H-H eclipsed conformations of acetaldehyde in the excited state . The least squares fitting analysis showed that the barrier heights in the excited state were higher than in the ground state. Finally, the isotopic shifts for the isotopic compounds of acetaldehyde were compared to the compounds with the similar deuterium substitution.

Analysis Of The A11a22 X 11a11 And A 33a22 X 1 electronic transitions in selenocarbonyl difluoride

The absorption spectrum of F2CSe in the 18800-21900 cm-1 region has been recorded at -770 C and 220 C under the conditions of medium resolution. The responsible electronic promotion is TI* + n excitation which leads to 3A2 and lA2 excited states. Progressions in vI', v2', v3" v4' and v4" have been identified in the spectrum and have been analyzed in terms of vibronic transitions between a planar ground state and a nQnplanar excited state. The - 3 - 1 - 1 - 1 origins of the a A2 + X Al and A A2 + X Al systems were assigned to the bands at 19018 cm-l and 19689 cm-l . This has given a singlet-triplet splittl. n g lA2 - 3A2 P f 671 cm -1 The out-of-plane wagging levels were found to be anharmonic. 1 -1 Barrier heights of 2483 cm- and 2923 cm were obtained for the lA2 and 3A2 upper states from a fitting of the energy levels of a Lorentzian-quadratic function to the observed levels in the out-of-plane wagging modes. 1 3 For the A2 and A2 states nonplanar equilibrium angles of 30.10 and 31.40 have been evaluated respectively. i

Creativity and the schizophrenia spectrum unveiled : the similarities and the differences

This study examined the commonalities and the differences between creativity and the schizophrenia spectrum. The variables measured as potential commonalities and differences were creativity, schizotypy, cognitive inhibition, spatial ability, balancing skills, positive and negative presence, absorption, mystical experiences, childhood abuse, and neuroticism. Three community groups were recruited, consisting of 31 artists, 10 people with schizophrenia, and 31 comparisons matched for gender and age with the artists. A larger student group consisting of 102 students was also recruited in order to examine the correlations among the same variables within a larger, more normative, group. The largest commonality between the artist and the schizophrenic groups, who represented the extreme end of the schizophrenia spectrum, was the propensity to mystical experiences. The greatest differences between the artist and the schizophrenic groups were that the artists were higher in creativity, performed better on spatial abilities, had better balance, had more positive states of presence, and were lower in neuroticism than the schizophrenic group. In the student group, creativity was correlated with spatial ability, positive presence, absorption, and mystical experiences. In addition, creativity was significantly related to two facets of schizotypy, unusual experiences and impulsive nonconformity. In other words, students high in certain facets of schizotypy, who may share certain characteristics with those who have schizophrenia, are higher in creativity, but people who are on the extreme end of the schizophrenia spectrum, who have been diagnosed with schizophrenia, are not. The differences between the artist and schizophrenic groups on spatial ability, balance, sense of presence, and neuroticism may help to determine whether mystical experiences help to integrate creative work or destabilize and disorganize the sense of self. It may be that mystical experiences can be used more positively by the creative individuals than people with schizophrenia, in that artists and people high in creativity were higher in positive traits such as positive presence and lower on negative variables such as neuroticism, and introvertive anhedonia.

Early detection and intervention for infants at risk of autism spectrum disorders

Autism is a developmental disorder that is characterized by abnonnal social interactions and communications as well as repetitive and restricted activities and interests. There is evidence of a genetic component, as 5% of younger siblings are diagnosed if their older sibling has been diagnosed. Autism is generally not diagnosed until age 3 at the earliest, yet it has been shown that early intervention for children with autism can greatly increase their functioning. Because of this, it is important that symptoms of autism are identified as early as possible so that diagnosis can occur as soon as possible to allow these children the earliest intervention. This thesis was divided into two parts. The first looked at the psychometrics of two proposed measures, the Parent Observation Checklist (POC), administered monthly, and the Infant Behavior Summary Evaluation (mSE), administered bimonthly, to see if they can be used with the infant population to identify autistic symptoms in infants who are at high risk for autism or related problems because they have an older sibling with autism. Study 1 reported acceptable psychometric properties of both the POC and IBSE in terms of test-retest reliability, internal consistency, construct validity and predictive validity. These results provide preliminary evidence that parent report measures can help to detect early symptoms of ASD in infants. The POC was shown to differentiate infants who were diagnosed from a matched group that was not diagnosed by 3 years of age. The second part of this thesis involved a telephone interview of parents who reported developmental and/or behavior problems in their high-risk infants that may be early signs of Autism Spectrum Disorder (ASD). During the interview, a service questionnaire was administered to see what interventions (including strategies recommended by the researchers) their at risk infants and affected older siblings were receiving, how satisfied the parents were with them and how effective they felt the interventions were. 3 Study 2 also yielded promising results. Parents utilized a variety of services for at risk infants and children with ASD. The interventions included empirically validated early intervention (e.g., ABA) to non-empirically validated treatments (e.g., diet therapy). The large number of nonempirically validated treatments parents used was surprising, yet parents reported being involved and satisfied, and thought that the services were effective. Parents' perceptions of their stress levels went down slightly and feelings of competence rose when they accessed services for their infants. Overall, the results of this thesis provide new evidence that parent-report methods hold promise as early detection instruments for ASD in at-risk infants. More research is needed to further validate these instruments as well as to understand the variables related to the parents' choice of early intervention for their at risk and affected children.

Crystal growth, Raman scattering and optical properties of the superconductor Cd2Re2O7(16O, 18O)/

Using the Physical Vapor Transport method, single crystals of Cd2Re207 have been grown, and crystals of dimensions up to 8x6x2 mm have been achieved. X-ray diffraction from a single crystal of Cd2Re207 has showed the crystal growth in the (111) plane. Powder X-ray diffraction measurements were performed on ^^O and ^^O samples, however no difference was observed. Assigning the space group Fd3m to Cd2Re207 at room temperature and using structure factor analysis, the powder X-ray diffraction pattern of the sample was explained through systematic reflection absences. The temperatiure dependence of the resistivity measurement of ^^O has revealed two structural phase transitions at 120 and 200 K, and the superconducting transition at 1.0 K. Using Factor Group Analysis on three different structiures of Cd2Re207, the number of IR and Raman active phonon modes close to the Brillouin zone centre have been determined and the results have been compared to the temperature-dependence of the Raman shifts of ^^O and ^*0 samples. After scaling (via removing Bose-Einstein and Rayleigh scattering factors from the scattered light) all spectra, each spectrum was fitted with a number of Lorentzian peaks. The temperature-dependence of the FWHM and Raman shift of mode Eg, shows the effects of the two structurjil phase transitions above Tc. The absolute reflectance of Cd2Re207 - '^O single crystals in the far-infrared spectral region (7-700 cm~^) has been measured in the superconducting state (0.5 K), right above the superconducting state (1.5 K), and in the normal state (4.2 K). Thermal reflectance of the sample at 0.5 K and 1.5 K indicates a strong absorption feature close to 10 cm~^ in the superconducting state with a reference temperature of 4.2 K. By means of Kramers-Kronig analysis, the absolute reflectance was used to calculate the optical conductivity and dielectric function. The real part of optical conductivity shows five distinct active phonon modes at 44, 200, 300, 375, and 575 cm~' at all temperatures including a Drude-like behavior at low frequencies. The imaginary part of the calculated dielectric function indicates a mode softening of the mode 44 cm~' below Tc.

Factors influencing the seasonal changes in primary productivity of the photosynthetic bacteria of Crawford Lake, Ontario

A naturally occurring population of photosynthetic bacteria, located in the meromictic Crawford Lake, was examined during two field seasons (1979-1981). Primary production, biomass, light intensity, lake transparency, pH and bicarbonate concentration were all monitored during this period at selected time intervals. Analysis of the data indicated that (l4C) bacterial photosynthesis was potentially limited by the ambient bicarbonate concentration. Once a threshold value (of 270 mg/l) was reached a dramatic (2 to 10 fold) increase in the primary productivity of the bacteria was observed. Light intensity appeared to have very little effect on the primary productivity of the bacteria, even at times when analyses by Parkin and Brock (1980a) suggested that light intensity could be limiting (i.e., 3.0-5.0 ft. candles). Shifts in the absorption maxima at 430 nrn of the .bacteriochlorophyll spectrum suggested that changes in the species or strain composition of the photosynthetic bacteria had occurred during the summer months. It was speculated that these changes might reflect seasonal variation in the wavelength of light reaching the bacteria. Chemocline erosion did not have the same effect on the population size (biomass) of the photosynthetic bacteria in Crawford Lake (this thesis) as it did in Pink Lake (Dickman, 1979). In Crawford Lake the depth of the chemocline was lowered with no apparent loss in biomass (according to bacteriochlorophyll data). A reverse current was. proposed to explain the observation. The photosynthetic bacteria contributed a significant proportion (10-60%) of the lake1s primary productivitya Direct evidence was obtained with (14C) labelling of the photosynthetic bacteria, indica.ting that the zooplankton were grazing the photosynthetic bacteria. This indicated that some of the photosynthetic bacterial productivity was assimilated into the food chain of the lake. Therefore, it was concluded that the photosynthetic bacteria made a significant contribution to the total productivity of Crawford Lake.

Heterogeneity of photosystem II as it occurs in domain specific regions of the thylakoid membrane of spinach (spinacia oleracia L.)

Thylakoid membrane fractions were prepared from specific regions of thylakoid membranes of spinach (Spinacia oleracea). These fractions, which include grana (83), stroma (T3), grana core (8S), margins (Ma) and purified stroma (Y100) were prepared using a non-detergent method including a mild sonication and aqueous two-phase partitioning. The significance of PSlla and PSII~ centres have been described extensively in the literature. Previous work has characterized two types of PSII centres which are proposed to exist in different regions of the thylakoid membrane. a-centres are suggested to aggregate in stacked regions of grana whereas ~-centres are located in unstacked regions of stroma lamellae. The goal of this study is to characterize photosystem II from the isolated membrane vesicles representing different regions of the higher plant thylakoid membrane. The low temperature absorption spectra have been deconvoluted via Gaussian decomposition to estimate the relative sub-components that contribute to each fractions signature absorption spectrum. The relative sizes of the functional PSII antenna and the fluorescence induction kinetics were measured and used to determine the relative contributions of PSlla and PSII~ to each fraction. Picosecond chlorophyll fluorescence decay kinetics were collected for each fraction to characterize and gain insight into excitation energy transfer and primary electron transport in PSlla and PSII~ centres. The results presented here clearly illustrate the widely held notions of PSII/PS·I and PSlIa/PSII~ spatial separation. This study suggests that chlorophyll fluorescence decay lifetimes of PSII~ centres are shorter than those of PSlIa centres and, at FM, the longer lived of the two PSII components renders a larger yield in PSlIa-rich fractions, but smaller in PSIlr3-rich fractions.

The electronic spectra and the determination of the excited state geometry of 3A" propynal /|nby Chhiu-Tsu Lin. -- 260 St. Catharines, Ont. : [s. n.],

Impurity free eluission spectra of HCCCHO and DCCCHO have been rephotographed using the electronic-energy-exchange method with benzene as a carrier gas. The near ultraviolet spectra of ReeCHO and DCCCHO were photographed in a sorption under conditions of high resolution with absorption path lengths up to 100 meters. The emission and absorption spectra of Propynal resulting from 3 n 1 t 1\ - A excitation has been reanalyzed in som.e detail. Botrl of the eH out-of-plane wagging modes were found to have negative anharmonicity. A barrier height of 56.8/0.0 cm- 1 and a nonplanar oft , , equilibrium angle of 17 3 /30 are calculated for the V 10/ lJ 11 modes. The in-plane and out-of-plane v1. brational modes in the 3A." and 1a~. ' elec ronic states of Propynal were subjected to a normal coordinate treatment in the approximat :on of tIle Urey-Bradley force field. From the relative oscillator strengths of the trans1·t1·0ns connect i ng t he v ibrat1•0n1ess lA' , state and t,he V1· bron1·C 3· if levels of the A state, the differences in equilibrium configuration were evaluated from an approximate Franck-Condon analysis based on the ground state normal coordinates. As this treatment gave 512 possible geometrical structures for the upper state, it 4 was necessary to resort to a comparison of the observed and calculated moments of inertia along with chemical intuition to isolate the structure. A test of the correctness of the calculated structure change and the vibrational assignment was raade by evaluating the intensities of the inplane and out-oi-plane fundarnental, sequence, and cross sequellce transitions y the exact Franck-Condon method.

The measurement of the optical absorption cross section of photosystem 1 and photosystem 2 from whole live cells of porphyridium cruentum, in light state 1 and light state 2

The optical cross section of PS I in whole cells of Porphyridium cruentum (UTEX 161), held in either state 1 or state 2, was determined by measuring the change in absorbance at 820nm, an indication of P700+; the X-section of PS2 was determined by measuring the variable fluorescence, (Fv-Fo)/Fo, from PS2. Both cross-sections were 7 determined by fitting Poisson distribution equations to the light saturation curves obtained with single turnover laser flashes which varied in intensity from zero to a level where maximum yield occurred. Flash wavelengths of 574nm, 626nm, and 668nm were used, energy absorbed by PBS, by PBS and chla, and by chla respectively. There were two populations of both PSi and PS2. A fraction of PSi is associated with PBS, and a fraction of PS2 is free from PBS. On the transition S1->S2, only with PBS-absorbed energy (574nm) did the average X-section of PSi increase (27%), and that of PS2 decrease (40%). The fraction of PSi associated with PBS decreased, from 0.65 to 0.35, and the Xsection of this associated PS 1 increased, from 135±65 A2 to 400±300A2. The cross section of PS2 associated with PBS decreased from 150±50 A2 to 85±45 A2, but the fraction of PS2 associated with PBS, approximately 0.75, did not change significantly. The increase in PSi cross section could not be completely accounted for by postulating that several PSi are associated with a single PBS and that in the transition to state2, fewer PSi share the same number of PBS, resulting in a larger X-section. It is postulated that small changes occur in the attachment of PS2 to PBS causing energy to be diverted to the attached PSi. These experiments support neither the mobile-PBS model of state transitions nor that of spillover. From cross section changes there was no evidence of energy transfer from PS2 to PSi with 668nm light. The decrease in PS2 fluorescence which occurred at this wavelength cannot be explained by energy transfer; another explanation must be sought. No explanation was found for an observed decrease in PSi yield at high flash intensities.

Transmission measurements using a new far-infrared set-up

A system comprised of a Martin-Puplett type polarizing interferometer and a Helium-3 cryostat was developed to study the transmission of materials in the very-far-infrared region of the spectrum. This region is of significant interest due to the low-energy excitations which many materials exhibit. The experimental transmission spectrum contains information concerning the optical properties of the material. The set-up of this system is described in detail along with the adaptations and improvements which have been made to the system to ensure the best results. Transmission experiments carried out with this new set-up for two different varieties of materials: superconducting thin films of lead and biological proteins, are discussed. Several thin films of lead deposited on fused silica quartz substrates were studied. From the ratio of the transmission in the superconducting state to that in the normal state the superconducting energy gap was determined to be approximately 25 cm-1 which corresponds to 2~/kBTc rv 5 in agreement with literature data. Furthermore, in agreement with theoretical predictions, the maximum in the transmission ratio was observed to increase as the film thickness was increased. These results provide verification of the system's ability to accurately measure the optical properties of thin low-Tc superconducting films. Transmission measurements were carried out on double deionized water, and a variety of different concentrations by weight of the globular protein, Bovine Serum Albumin, in the sol, gel and crystalline forms. The results of the water study agree well with literature values and thus further illustrate the reproducibility of the system. The results of the protein experiments, although preliminary, indicate that as the concentration increases the samples become more transparent. Some weak structure in the frequency dependent absorption coefficient, which is more prominent in crystalline samples, may be due to low frequency vibrations of the protein molecules.

A naturalistic observation of the play behaviour of children with autism spectrum disorders /

Cognitive and social levels of play engaged in by four-to-eight-year-old children with autism spectrum disorders were examined in naturalistic classroom settings. In addition, play at home was compared with play at school via parent and educator interviews. Seventeen school-age children, their educators and caregivers participated in the study. The most frequently observed play behaviours included parallel-functional play, adult interactions and solitary-functional play. The play of the children in the current study was consistent with that of typically-developing preschoolers. Mothers and educators did not differ significantly in their perspectives of the participants' play behaviours. In general, educators' and caregivers' reports were positively related to researcher observations of participants' play behaviours. Methodological considerations and practical implications for the findings are discussed.

Exploring an emotion intervention for preschoolers with autism spectrum disorder /

The purpose of this multiple case study was 1) to explore the effectiveness of an emotions recognition program for preschoolers with Autism Spectrum Disorders (ASD), and 2) to investigate one parent's perception of the emotions program. To address these objectives, the emotion unit scores of 7 preschoolers with ASD aged 3 to 5 years old (1 female, 6 males) were graphed and analyzed using visual inspection. In addition, the mother of 1 participant was interviewed to explore her perceptions of the emotions program and emotional learning. Overall, results revealed that participants' emotion recognition scores increased over the course of the emotions unit. The parent reported improvements in her son's expression and understanding of emotion, but noted that he continued to have difficulty with regulation of emotion. Implications for theory, education, and future research are discussed.

Cognitive set, absorption, and achievement as moderators of the perceptual closure effect in picture priming /

The present study examined individual differences in Absorption and fantasy, as well as in Achiievement and achievement striving as possible moderators of the perceptual closure effect found by Snodgrass and Feenan (1990). The study also examined whether different instructions (experiential versus instrumental) interact with the personality variables to moderate the relationship between priming and subsequent performance on a picture completion task. 1 28 participants completed two sessions, one to fill out the MPQ and NEO personality inventories and the other to complete the experimental task. The experimental task consisted of a priming phase and a test phase, with pictures presented on a computer screen for both phases. Participants were shown 30 pictures in the priming phase, and then shovm the 30 primed pictures along with 30 new pictures for the test phase. Participants were randomly assigned to receive one of the two different instruction sets for the task. Two measures of performance were calculated, most fragmented measure and threshold. Results of the present study confirm that a five-second exposure time is long enough to produce the perceptual closure effect. The analysis of the two-way interaction effects indicated a significant quadratic interaction of Absorption with priming level on threshold performance. The results were in the opposite direction of predictions. Possible explanations for the Absorption results include lack of optimal conditions, lack of intrinsic motivation and measurement problems. Primary analyses also revealed two significant between-subject effects of fantasy and achievement striving on performance collapsed across priming levels. These results suggest that fantasy has a beneficial effect on performance at test for pictures primed at all levels, whereas achievement striving seems to have an adverse effect on performance at test for pictures primed at all levels. Results of the secondary analyses with a revised threshold performance measure indicated a significant quadratic interaction of Absorption, condition and priming level. In the experiential condition, test performance, based on Absorption scores for pictures primed at level 4, showed a positive slope and performance for pictures primed at levels 1 and 7 based on Absorption showed a negative slope. The reverse effect was found in the instrumental condition. The results suggest that Absorption, in combination with experiential involvement, may affect implicit memory. A second significant result of the secondary analyses was a linear three-way interaction of Achievement, condition and priming level on performance. Results suggest that as Achievement scores increased, test performance improved for less fragmented primed pictures in the instrumental condition and test performance improved for more highly fragmented primes in the experiential condition. Results from the secondary analyses suggest that the revised threshold measure may be more sensitive to individual differences. Results of the exploratory analyses with Openness to Experience, Conscientiousness and agentic positive emotionality (PEM-A) measures indicated no significant effects of any of these personality variables. Results suggest that facets of the scales may be more useful with regard to perceptual research, and that future research should examine narrowly focused personality traits as opposed to broader constructs.

Pigment orientation changes detected by low temperature linear dichroism spectroscopy: cold-hardening transition in phycobilisome-containing organisms

Low temperature (77K) linear dichroism spectroscopy was used to characterize pigment orientation changes accompanying the light state transition in the cyanobacterium, Synechococcus sp. pee 6301, and cold-hardening in winter rye (Secale cereale L. cv. Puma). Samples were oriented for spectroscopy using the gel squeezing method (Abdourakhmanov et aI., 1979) and brought to 77K in liquid nitrogen. The linear dichroism (LD) spectra of Synechococcus 6301 phycobilisome/thylakoid membrane fragments cross-linked in light state 1 and light state 2 with glutaraldehyde showed differences in both chlorophyll a and phycobilin orientation. A decrease in the relative amplitude of the 681nm chlorophyll a positive LD peak was observed in membrane fragments in state 2. Reorientation of the phycobilisome (PBS) during the transition to state 2 resulted in an increase in core allophycocyanin absorption parallel to the membrane, and a decrease in rod phycocyanin parallel absorption. This result supports the "spillover" and "PBS detachment" models of the light state transition in PBS-containing organisms, but not the "mobile PBS" model. A model was proposed for PBS reorientation upon transition to state 2, consisting of a tilt in the antenna complex with respect to the membrane plane. Linear dichroism spectra of PBS/thylakoid fragments from the red alga, Porphyridium cruentum, grown in green light (containing relatively more PSI) and red light (containing relatively more PSll) were compared to identify chlorophyll a absorption bands associated with each photosystem. Spectra from red light - grown samples had a larger positive LD signal on the short wavelength side of the 686nm chlorophyll a peak than those from green light - grown fragments. These results support the identification of the difference in linear dichroism seen at 681nm in Synechococcus spectra as a reorientation of PSll chromophores. Linear dichroism spectra were taken of thylakoid membranes isolated from winter rye grown at 20°C (non-hardened) and 5°C (cold-hardened). Differences were seen in the orientation of chlorophyll b relative to chlorophyll a. An increase in parallel absorption was identified at the long-wavelength chlorophyll a absorption peak, along with a decrease in parallel absorption from chlorophyll b chromophores. The same changes in relative pigment orientation were seen in the LD of isolated hardened and non-hardened light-harvesting antenna complexes (LHCII). It was concluded that orientational differences in LHCII pigments were responsible for thylakoid LD differences. Changes in pigment orientation, along with differences observed in long-wavelength absorption and in the overall magnitude of LD in hardened and non-hardened complexes, could be explained by the higher LHCII monomer:oligomer ratio in hardened rye (Huner et ai., 1987) if differences in this ratio affect differential light scattering properties, or fluctuation of chromophore orientation in the isolated LHCII sample.