A classroom-based investigation of reciprocal teaching at the grade seven level

This study assessed the effectiveness of a reciprocal teaching program as a method of teaching reading comprehension, using narrative text material in a t.ypical grade seven classroom. In order to determine the effectiveness of the reciprocal teaching program, this method was compared to two other reading instruction approaches that, unlike rcciprocal teaching, did not include social interaction components. Two intact grade scven classes, and a grade seven teacher, participated in this study. Students were appropriately assigned to three treatment groups by reading achievement level as determined from a norm-referenced test. Training proceeded for a five week intervention period during regularly scheduled English periods. Throughout the program curriculum-based tests were administered. These tests were designed to assess comprehension in two distinct ways; namely, character analysis components as they relate to narrative text, and strategy use components as they contribute to student understanding of narrative and expository text. Pre, post, and maintenance tests were administered to measure overall training effects. Moreover, during intervention, training probes were administered in the last period of each week to evaluate treatment group performance. AU curriculum-based tests were coded and comparisons of pre, post, maintenance tests and training probes were presented in graph form. Results showed that the reciprocal group achieved some improvement in reading comprehension scores in the strategy use component of the tests. No improvements were observed for the character analysis components of the curriculum-based tests and the norm-referenced tests. At pre and post intervention, interviews requiring students to respond to questions that addressed metacomprehension awareness of study strategies were administered. The intelviews were coded and comparisons were made between the two intelVicws. No significant improvements were observed regarding student awareness of ten identified study strategies . This study indicated that reciprocal teaching is a viable approach that can be utilized to help students acquire more effective comprehension strategies. However, the maximum utility of the technique when administered to a population of grade seven students performing at average to above average levels of reading achievement has yet to be determined. In order to explore this issue, the refinement of training materials and curriculum-based measurements need to be explored. As well, this study revealed that reciprocal teaching placed heavier demands on the classroom teacher when compared to other reading instruction methods. This may suggest that innovative and intensive teacher training techniques are required before it is feasible to use this method in the classroom.

A geochemical and paleoceanographic investigation using marine molluscs of the late Quaternary marine submergences Quebec, Ontario, British Columbia

Sedjrrlents deposited in the Late Quaternary marine sUbrnergences that follov'ted the deglaciation of Ontario} Quebec., and 6ritlst-1 Columbia often contaln an abundant nlarlne invertebrate macrofauna. The rnacrofauna~ dotYllnated by aragonitic pelecypods} is fully preserved In their original mineralogy and cherrlistry 8S deternl1ned by x-ray dlffractlon., scannlng electron tl-,lcroscoDY., trace and r1l1 nor elet11ent analyses and stable isotopes. Ttle trace elernent and stable isotope geochen-Ilstry of chernlcal1y unaltered aragorlitlc molluscs can be used to determine paleoter1-lperatures and paleosallnltles." HO\Never} corrections need to be tllade \fvtlen deterrTIlnlng oxygen-isotope paleotenlperi:ttures due to the lnfluence of isotopically 11gtlt glaciol rneltv-laters and reduced sal1nltles. Ttle eastern Laurentide Ice Sheet probably had an o:~ygen lS0tOP1C composition as low as -8e) 0/00 (Sr1[IW). In additl0fl} corrections need to be rnade to the carbonlsotope values, before salinity deterrnlnatlons are t11ade., due to the reJjuctlon of the terrestrial carbon bl0rnass during glac1al maxlrna. Using geochernlcal data frot11 537 marlne n-'8crolnvertebrates frorTI 72 localities in soutt-,easter Ontarl0 and southern Quebec, it tras been deterrnined that the Late Quaternary Char1lplaln Sea \N6S density stratified along salinity and temperatlJre gradients. The deep-\h/aters of tt-,e Charnplaln Sea tlad salinities that ranged frorn 31 to 36 ppt} and terrlperatures of 00 to 5°C. Conversely.. the st1alloy./-\f*later regirrle of ttle Ctlarnplaln Sea tlad sal1nltles that ranged fron-, 24 to 33 ppt} Y.tltt1 terrlperatures ranglng from 5° to 15°C. Tr,8 rrlajorl rnlnor1 and trace e1et1-,ent geochernlcal analysls of 155 marine lnvertebrates frorn 4 10C611t1es of tt-,e Late Quaternary Ft. Langley Forrnatlon and Capl1ano Sedlments;. souttl\Nestern Brltlsh Columblal suggest l t~lat the 'waters of the o-,arlne lnundation that fol1o....ved the retreating Cordl11eran Ice Sheet had sal1nltles ranglng frorn 32 to 3f. DPt.

An experimental investigation of dechanneling in copper single crystals

This investigation comprises a comparison of experimental and theoretical dechanneling of MeV protons in copper single crystals. Dechanneling results when an ion's transverse energy increases to the value where the ion can undergo small impact parameter collisions with individual atoms. Depth dependent dechanneling rates were determined as functions of lattice temperature, ion beam energy and crystal axis orientation. Ion beam energies were IMeV and 2MeV,temperatures ranged from 35 K to 280 K and the experiment was carried out along both the (lOa) and <110) axes. Experimental data took the form of aligned and random Rutherford backscattered energy spectra. Dechanneling rates were extracted from these spectra using a single scattering theory that took explicit account of the different stopping powers experienced by channeled and dechanneled ions and also included a correction factor to take into account multiple scattering effects along the ion's trajectory. The assumption of statistical equilibrium and small angle scattering of the channeled ions allows a description of dechanneling in terms of the solution of a diffusion like equation which contains a so called diffusion function. The diffusion function is shown to be related to the increase in average transverse energy. Theoretical treatments of increase in average transverse energy due to collisions of projectiles with channel electrons and thermal perturbations in the lattice potential are reviewed. Using the diffusion equation and the electron density in the channel centre as a fitting parameter dechanneling rates are extracted. Excellent agreement between theory and experiment has been demonstrated. Electron densities determined in the fitting procedure appear to be realistic. The surface parameters show themselves to be good indicators of the quality of the crystal.

An investigation into the oxidation of organic sulphides, organic selenides and simple hydrocarbons by Mortierella isabellina NRRL 1757

The work presented in this thesis is divided into three separate sections 4!> Each' 'section is involved wi th a different problem, however all three are involved with a microbial oxidation of a substrate~ A series of 'aryl substituted phenyl a.nd be,nzyl methyl sulphides were oxidized to the corre~pondi~g sulphoxides by 'Mo:rtierellai's'a'b'e'llina NRR.L17'S7 @ For this enzymic Qxidation, based on 180 labeled experiments, the oxygen atom is derived fr'orn the atmosphere and not from water. By way of an u~.traviolet analysis, the rates of oxidation, in terms of sulphox~ de appearance, were obtained and correlated with the Hatnmett p s~grna constants for the phenyl methyl sulphide series. A value of -0.67 was obtained and, is interpreted in terms of a mechanism of oxidation that involves an electrophilic attack on the sulphide sulphur by an enzymic ironoxygen activated complex and the conversion of the resulti!lg sulphur cation to sulphoxide. A series of alkyl phenyl selen~des have been incubated with the fu~gi, Aspergillus niger ATCC9l42, Aspergillus fO'etidus NRRL 337, MIIJisabellina NF.RLl757 and'He'lminth'osparium sp'ecies NRRL 4671 @l These fu?gi have been reported to be capable of carrying out the efficient oxidation of sulphide to sulphoxide, but in no case was there any evidence to supp'ort the occurrence of a microbialox,idation. A more extensive inves·t~gation was carried out with'M,e 'i's'a'b'e'l'l'i'na, this fu~gus was capable of oxidizing the correspondi~g sulphides to sulphoxi.de·s·$ Usi:ng a 1abel.edsubstra.te, [Methyl-l4c]-methyl phenyl selenide, the fate of this compound was invest~gated followi!lg an i'ncubation wi th Me isabellina .. BeSUldes th. e l4C-ana1YS1Q S-,'. a quant"ltta"lve selen'lum ana1Y"S1S was carried out with phenyl methyl selenide. These techniques indicate that thesel'enium was capable of enteri!1g thefu!1gal cell ef'ficiently but that s'ome metabolic cleav~ge of the seleni'um-carbon bond' may take plac'e Ie The l3c NMR shifts were assigned to the synthesized alkyl phenyl sulphides and selenides@ The final section involved the incubation ofethylben~ zene and p-e:rtr.hyltoluene wi th'M ~ 'isab'e'llina NRRL 17574b Followi~ g this incubation an hydroxylated product was isolated from the medium. The lH NMR and mass spectral data identify the products as I-phenylethanol and p-methyl-l-phenylethanol. Employi!lg a ch'iral shift re~gent,tri~ (3-heptafluorobutyl-dcamphorato)'- europium III, the enantiomeric puri ty of these products was invest~gated. An optical rotation measurement of I-phenylethanol was in ~greement with the results obtained with the chiral shift re~gen,te 'M.isabe'l'lina is capable of carryi~g out an hydroxylation of ethylbenzene and p-ethyltoluene at the ~ position.

An investigation into differences between indoleacetic acid and fusicoccin in their influence on RNA synthesis, protein synthesis and growth in Avena coleoptile tissue

Growth stimulation of Avena coleoptile tissue by indoleacetic acid (IAA) and fusicoccin (FC) was compared by measuring both their influence on RNA and protein synthesis during IAA or FC stimulated growth. FC stimulated growth more than IAA during the initial four hour exposure, after which the growth rate gradually declined to the control rate. FC, but not IAA, increased the uptake of 3H-Ieucine into tissue and the specific radioactivity of extracted protein. Cycloheximide inhibited the incorporation of 3H-Ieucine into protein by approximately 60% to 70% in all cases. In the presence of cycloheximide 3H-radioactivity accumulated in FC-treated tissue, whereas IAA did not seem to influence 3H-accumulation. These results suggest that FC stimulated leucine uptake into the tissue and that increased specific activity of coleoptile protein is due to increased leucine uptake, not an increased rate of protein synthesis. There was no measurable influence of IAA and/or FC on RNA and protein synthesis during the initial hours of a growth stimulation. Inhibitors of RNA and protein synthesis, actinomycin D and cycloheximide, respectively, severely inhibited IAA enhanced growth but only partially inhibited FC stimulated growth. The data are consistent with suggestions that a rapidly turning over protein participates in IAA stimulated growth, and that a continual synthesis of RNA and proteins is an absolute requirement for a long term growth response to IAA. On the contrary, FC-stimulated growth exhibited less dependency on the transcription and translation processes. The data are consistent with proposals suggesting different sites of action for FC and IAA stimulated growth. l?hen compared to CO2-free air, CO2 at 300 ppm had no significant influence on coleoptile growth and protein synthesis in the presence or absence of lAA or FC. Also, I mM malate, pH 6.0 did not influence growth of coleoptiles in the presence or absence of lAA. This result was obtained despite reports indicating that 300 ppm CO2 or I mM malate stimulates growth and protein synthesis. This lack of difference between CO2-treated and untreated tissue could indicate either that the interstitial space CO2 concentration is not actually different in the two treatments due to significant endogenous respiratory CO2 or else the data would suggest a very loose coupling between dark CO2 fixation and growth. IAA stimulated the in vivo fixation of 14c-bicarbonate (NaHI4c03) by about 25% and the addition of cycloheximide caused an inhibition of bicarbonate fixation within 30 min. Cycloheximide has also been reported to inhibit IAA-stimulated H+ excretion. These data are consistent with the acid growth theory and suggest that lAA stimulated growth involves dark CO2 fixation. The roles of dark CO2 fixation in lAA-stimulated growth are discussed.