Solid-state NMR and x-ray diffraction investigations of sphingomyelin model membranes

The only sphingolipid occurring naturally in mammalian cells, sphingomyelin (SM) is of great importance. Having predominantly long, saturated acyl chains it has an unusually high melting temperature (around physiological temperature) and has been strongly associated with lipid microdomains often referred to as “lipid rafts”. These domains are proposed to be enriched in SM and cholesterol (Chol) and have been linked to many cell processes and disease states. Despite the important role SM plays in the cell membrane, there is relatively little published data available in the literature. The first chapter of this work investigates the behaviour of SM from three natural sources, bovine brain (BBSM), egg yolk (EYSM) and milk (MSM). This allows a comparison of the phase behaviour in terms of the different chain compositions in each extract. The results show that the extracts differ in their gel phase structures and we present the first x-ray diffraction data for a ripple phase (Pβ’) in BBSM and EYSM. At sufficiently high concentrations, Chol acts to disrupt the gel phase (Lβ) and order the fluid phase (Lα) of SM, leading to the formation of the ‘intermediate’ liquid ordered (Lo) phase. This phase retains characteristics of both the Lβ and Lα phases and has been strongly associated with lipid rafts. Using a combination of x-ray diffraction and 31P solid-state NMR, we have investigated the disruption of the gel phase of BBSM at low Chol concentrations. The results show disruption of the regular packing of the gel phase and also the removal of the ripple phase at 15mol% Chol. Finally, time-resolved x-ray diffraction techniques were utilised to investigate the kinetics of the different lamellar transitions observed. The Lβ to Lα and the Pβ’ to Lα transitions are compared in MSM and BBSM

Diversity of the Beneficial Bacterium Oxalobacter formigenes Isolated from the Human Gut

Oxalobacter formigenes is an anaerobic, oxalate degrading organism that colonizes in the mammalian intestinal tract. Currently, O. formigenes is divided into two groups via PCR of the oxc gene. Pulsed field gel electrophoresis (PFGE) is a technique used to resolve large pieces of DNA. Typically, PFGE is used to identify differences between strains for pathogenic bacteria, but this study sought to use it to further understand the diversity of a probiotic organism. This study aimed to develop a methodology for utilizing PFGE to examine O. formigenes. The methodology involved lysing O. formigenes cells in plugs, first in proteinase K, followed by lysozyme. The cells were digested using XbaI and SacI, and run on a BioRad CHEF Mapper®. While many of the methods tested failed to produce results, attempting the two step method with proteinase K and lysozyme, resulted in bands that became clearer and were able to be analyzed. Differences were observed between strains of O. formigenes. Even strains from the more conserved group I showed variation in their DNA fingerprint using this method

Therapeutic Intervention or Rider Influence on the Electromyographic Activity And Kinematics of Horses

Core strengthening and postural stability are desired outcomes of certain therapeutic exercises performed in horses. This study aimed to quantify changes in muscle activation at a walk and trot in horses traveling over eight consecutive ground poles evenly spaced (at 30 inches for walk and 48 inches for trot) in parallel fashion in a straight line, and with hindquarter and abdominal elastic resistance bands applied at 25% stretch. Surface electromyography (sEMG) data were collected for the longissimus dorsi and rectus abdominus muscles in six horses. A 2x2 repeated measures ANOVA was performed for each muscle to test for significant differences in differences in normalized average rectified values and maximum low pass signals. Within subject effects were reported, followed by post-hoc pairwise comparisons to evaluate differences between the conditions of with or without ground poles or elastic resistance bands. The use of ground poles at a walk resulted in a significant (p \u3c 0.05) increase in the maximum low pass value bilaterally in the longissimus dorsi and rectus abdominus muscles, with an increase in the average rectified value bilaterally in the rectus abdominus muscles and right longissimus dorsi muscle. The use of ground poles at a trot resulted in a significant increase in the maximum low pass value bilaterally in the rectus abdominus muscles. The hindquarter and abdominal elastic resistance bands resulted in a respective 27% and 27.2% increase in the mean average rectified value of the left and right RA muscles, however this only reached statistical significance in the left RA (p \u3c 0.05). These findings provide support regarding changes in muscle activation when using ground poles to increase core and epaxial muscle engagement. While a significant effect on core muscle activation was identified with the elastic resistance bands at a trot, further research is needed in this area to further characterize their effects on muscle activation

Perpetrators of child sexual abuse an exploration of group treatment outcomes.

Source: Masters Abstracts International, Volume: 40-07, page: . Thesis (M.S.W.)--University of Windsor (Canada), 1989

Parenting a child with chronic illness as they transition into adulthood:a systematic review and thematic synthesis of parents’ experiences

Objective - To understand how parents view and experience their role as their child with a long-term physical health condition transitions to adulthood and adult healthcare services. Methods - Five databases were systematically searched for qualitative articles examining parents’ views and experiences of their child’s healthcare transition. Papers were quality assessed and thematically synthesised. Results - Thirty-two papers from six countries, spanning a 17-year period were included. Long-term conditions were diverse. Findings indicated that parents view their child’s progression toward self-care as an incremental process which they seek to facilitate through up-skilling them in self-management practices. Parental perceptions of their child’s readiness, wellness, competence and long-term condition impacted on the child’ progression to healthcare autonomy. A lack of transitional healthcare and differences between paediatric and adult services served as barriers to effective transition. Parents were required to adjust their role, responsibilities and behaviour to support their child’s growing independence. Conclusion - Parents can be key facilitators of their child’s healthcare transition, supporting them to become experts in their own condition and care. To do so, they require clarification on their role and support from service providers. Practice Implications - Interventions are needed which address the transitional care needs of parents as well as young people

Ice Scours in the Sediments of Glacial Lake Iroquois, Prince Edward County, Eastern Ontario

Straight or slightly curved ice scours are found in thin glacilacustrine sediment of eastern Lake Iroquois, especially near the crest of an escarpment in Prince Edward County. They are large (to 3.57 km long and 174 m wide), shallow (about 1 m deep) and oriented in a nearly westerly direction. Irregular ridges of sediment have been pushed up along the sides and at the western end of some scours. Bedrock is near the ground surface, but had little influence on the formation of the scours. Based on their shape, location and pattern, we conclude that the scours were most likely formed in shallow water of the short-lived Sydney phase of Lake Iroquois by lake ice driven by prevailing northeasterly winds from the retreating Laurentide Ice Sheet.On trouve des sillons glaciels, rectilignes ou courbes, dans des sédiments lacustres de l'est du Lac Iroquois, en particulier près du sommet d'un escarpement dans le comté de Prince Edward. Ces sillons sont larges (jusqu'à 3,57 km de longueur et 174 m de largeur), peu profonds (environ 1 m) et orientés vers l'ouest. Des bourrelets irréguliers de sédiments apparaissent en bordure et à l'extrémité ouest de quelques dépressions. Le substratrum affleure presque, mais a eu peu d'influence sur la formation des sillons. En se fondant sur leur forme, leur emplacement et leur agencement, on en conclut que les sillons ont été formés dans les eaux peu profondes du Lac Iroquois au cours de la courte phase de Sydney, par les glaces du lac poussées par les vents dominants du nord-est, en provenance de l'Inlandsis laurentidien alors en retrait.,1EZlOBbIE B0P03Zlbl B HAHOCAX 3AMEP3lilErO HP0KE3CK0r0 03EPA. TPAOCTBO nPMHU 3ZtBAPZl. BOCTOMHbM OHTAPHO. B TOHKHX JieaOBblX HaHOCaX B BOCTOi-lHOH HacTH Hpok-e3Ckoro 03epa ocoôeHHO pa/ioM c rpefiHeM KpyToro ck'JioHa rpa(|)CTBa flpnnu dnsapn MOAHO na6^ioziaTb npSMbie tum cnerka HSBHBaiolilnecn .neaoBbie 6opo3AU. OHM HMeioT fkyibunie pa3Mepw (no 3.57 KM B JWHHy H 174 M B mnpnHyi. MCAKM H opueH TnpoBanbi npenMylilecTBeHHO Ha 3anaa. HepeperyjiapHbie rpefJHH HaHocoB HaxoflflT-CJi no fjoKaM H B 3anaziHbix OKOHLiaHiiax HeKOTopwx 6opo3/j. HecMOTpa Ha TO. MTO nopo/ia HaxoziHTCfi 6^H3KO OT noBepxHocTH rpyHTa. eë B^nflnne Ha (|K>pMnpoBaHHe mix 6opo34 HeBCiHKO. Ha ocHOBaHiin (tjopMbl, pacnano*eHHfl H piicyHKa 5opo3/t /icnaeTC" BUBO/1, MTO OHH. CKOpee BCerO. f)W/lH ClpOpMHpOBaHbl B MeJIKHX BOZiaX MpOKe3CKOrO 03epa BO BpeMfl KopoTkOH (ba3bi Cn/iHeiï nozi B03,aeHCTBi(eM 03ëpnoro j\t>j\a, HaitccetiHoro /lOMHHHpyiOlilHMH CeBepOBOCTOMHhlMH BeTpaMH OT OTcTynaioUJero /laBpenTHitcKoro MaTepnKOBoro neaHHKa