Standing-wave-excited multiplanar fluorescence in a laser scanning microscope reveals 3D information on red blood cells

Standing-wave excitation of fluorescence is highly desirable in optical microscopy because it improves the axial resolution. We demonstrate here that multiplanar excitation of fluorescence by a standing wave can be produced in a single-spot laser scanning microscope by placing a plane reflector close to the specimen. We report that the relative intensities in each plane of excitation depend on the Stokes shift of the fluorochrome. We show by the use of dyes specific for the cell membrane how standing-wave excitation can be exploited to generate precise contour maps of the surface membrane of red blood cells, with an axial resolution of ~90 nm. The method, which requires only the addition of a plane mirror to an existing confocal laser scanning microscope, may well prove useful in studying diseases which involve the red cell membrane, such as malaria.Comment: 15 pages, 4 figures; changed the discussion of narrow-band detected fringes (Fig. 3) to describe the phenomenon as a moire pattern between the excitation and emission standing-wave fields, rather than a beats pattern; added DiI(5)-labelled red blood cell in Fig. 4 to show that standing-wave fringes are present even when the dye excitation wavelength is outside the haemoglobin absorption ban

Characterising antibody immunity and ageing in a short-lived teleost

Ageing individuals exhibit a pervasive decline in adaptive immune function, with important implications for health and lifespan. Systemic changes observed in the structure and diversity of antibody repertoires with age are thought to play an important role in this immunosenescent phenotype; however, the relatively long lifespan of most vertebrate model organisms makes thorough investigation of the ageing repertoire challenging. As a naturally short-lived vertebrate, the turquoise killifish (Nothobranchius furzeri) offers an exciting new opportunity to study the ageing of the adaptive immune system in general and antibody repertoires in particular. In this thesis, I used a combination of existing genomic assemblies and new sequencing data to assemble and characterise the immunoglobulin heavy chain (IGH) locus sequence in the turquoise killifish and compare it to those of closely related species, revealing a history of dynamic locus evolution and repeated duplication and loss of the specialised mucosal isotype IGHZ. The N. furzeri locus itself lacks IGHZ, making it one of the few known teleost species not to possess this isotype. These results support a high rate of evolution in teleost IGH loci and set a strong foundation for the study of comparative evolutionary immunology in cyprionodontiform fishes. Having characterised the IGH locus sequence in N. furzeri, I used it to establish targeted immunoglobulin sequencing in this species, enabling quantitative interrogation of the antibody repertoire. Applying this protocol to whole-body killifish samples revealed complex and individualised antibody repertoires which decline rapidly in within-individual diversity and increase in between-individual variability with age, demonstrating that turquoise killifish exhibit a rapid repertoire-ageing phenotype in line with their short lifespans. This loss of diversity with age was particularly strong in isolated gut samples, a phenomenon that may be related to the constant strong antigenic exposure experienced at mucosal surfaces and has not been previously investigated in a vertebrate model. Taken together, these results establish the turquoise killifish as a novel model for vertebrate immunosenescence and lay the groundwork for future interrogation of -- and intervention in -- adaptive-immune ageing

Homeostasis and Polymorphism in Vernal Development of Chaoborus Americanus

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/119057/1/ecy19735461247.pd

Rare-Earth Elements in the Nechalacho Deposit, NWT: Hydrothermal Controls on Mineralogy and Fractionation

The Nechalacho rare-metal (REE-Y-Nb-Ta-Zr) deposit, is hosted by a sequence of altered, layered sodic syenites. Three distinct whole-rock chemical signatures are evident. Two of these signatures have high P, of which, one has high light REE (LREE) but low heavy REE (HREE) (type 1), and one has high HREE (type 2). The third signature has low P and high HREE, LREE and Zr (type 3). Type 1 and 2 signatures represent abundant monazite-(Ce) (LREEPO4) and xenotime-(Y) ((Y,HREE)PO4), respectively. Type 3 represents zircon and a variety of non-phosphate REE minerals, such as allanite-(Ce), fergusonite-(Y) ((Y,REE)NbO4), or bastnäsite-(Ce) (REECO3F). The results indicate that the ore mineralogy can in part be predicted from whole-rock chemistry. Phosphates are an important reservoir for the LREE at the Nechalacho deposit. Two main textural types of monazite-(Ce) have been recognized: columnar and equant. These can also be distinguished chemically based on U and Th concentrations. The columnar monazite-(Ce) is associated with an early magnetite-biotite-quartz alteration, whereas the equant monazite-(Ce) is associated with later carbonate-chlorite-fluorite alteration. Xenotime-(Y) also occurs in various habits, such as rods and anhedral aggregates. The deposit is divided into Upper and Basal zones, the Basal Zone having a higher HREE/LREE ratio than the Upper Zone. It has been previously proposed that the LREE were transported from magmatic eudialyte in the Basal Zone to higher in the system by hydrothermal fluids and precipitated there as LREE minerals. A recent geochemical model predicted that a series of pulses of aqueous fluid transporting REE, passing through a P-bearing nepheline syenite would precipitate monazite crystals that were progressively more depleted in HREE (relative to the starting fluid) with increasing distance from the source (height in the system). The REE chemistry of monazite from Nechalacho, obtained using LA-ICP-MS, does not support this model for the origin of LREE mineralization because the concentrations of HREE in monazite show no consistent decrease upward in the intrusive body, which suggests, along with the textural variability of the phosphates and their association with different assemblages, that the genesis of the LREE mineralization was caused by multi-stage alteration and its genesis is more complex than the proposed models imply. Fluid inclusion microthermometry on primary fluid inclusions in quartz and xenotime-(Y) indicate that the alteration fluids had salinities of ~8 to 13 wt.% NaCl equivalent, and temperatures of ~240 to 590 °C, and were different from those that altered the nearby T Zone

Restorative justice dialogue: The Impact of Mediation and Conferencing on Juvenile Recidivism

This is the first meta-analysis that examined the effectiveness of the two most prominent restorative justice dialogue programs in reducing juvenile recidivism. The use of meta-analytic methods provides a useful means for summarizing diverse research findings across restorative justice studies and synthesizing these findings in an objective manner. The use of an effect size is an easily interpreted way of assessing the strength of an intervention effect

Evaluating the Effectiveness of Cognitive-Behavioral Treatment of Residual Symptoms and Impairment in Schizophrenia

This study evaluated the effectiveness of cognitive-behavioral interventions in the treatment of persons with schizophrenia who experienced significant residual symptoms and impaired functioning despite their adherence to medication. The study used an aggregated AB single-system research design across 22 participants to evaluate change in clinical outcomes. Standardized measures of psychosocial functioning, severity of symptoms, attainment of treatment goals, and severity of the impact of illness on self-concept were used to assess change during the course of 18 months of treatment. Of the clients, 86% made statistically significant improvement in psychosocial functioning; 82% of the clients made statistically significant reduction in severity of psychiatric symptoms. All 22 clients exceeded the expected level of attainment of treatment goals. There was a statistically significant reduction in the negative impact of illness on sense of self. Findings support the effectiveness of cognitive-behavioral interventions in schizophrenia

Finding A Place in the World: The Experience of Recovery from Severe Mental Illness

This hermeneutic phenomenological study of 45 adults with serious and persistent mental illness (SPMI) examines the experience of recovery over 3 years. After a brief review of the results from the first two phases, this article reports the findings from the third phase of the recovery process. Five essential themes are identified: (1) reintegration in the community; (2) reintegration with family and friends; (3) reintegration with the case manager; (4) reintegration with oneself; (5) barriers to social inclusion. Findings highlight the unmet needs for consumers in their relationships with case managers and barriers to inclusion at the macro level. Implications for practice include the delineation of client and case manager tasks specific to each essential theme