Langerhans' Cells and Local Cellular Immunity in the Cervix Uteri

Dermatological research has shown there is a likely role for Langerhans' cells in initiating the local immune response. They are known to act as antigen presenting cells. Antigen presentation is essential for the generation of the T-cell response. The process involves helper T-cell interaction in the afferent limb of the immune response, with cytotoxic T-cells involved in efferent response. The resultant immune response has been shown to be dependent on the numbers of Langerhans' cells in the epithelium. T-cell mechanisms are primarily involved in immunity to tumours and to viral infections. The study was designed to investigate the possible role of the Langerhans' cell and local immune system in the cervix in relation to neoplastic changes especially since a virus - human papillomavirus (HPV) - is currently thought to be implicated in the aetiology of cervical neoplasia. The investigation of the local immune system with special regard to tumour immunosurveillance is relevant and well suited to studies in the cervix, although access to tissue is limited without specialised techniques such as colposcopy and biopsy. The well documented and easily identifiable preinvasive phase associated with carcinoma of cervix makes it possible to study the whole spectrum of neoplastic change in the cervix. The study therefore involved examination of normal patients, those with cervical carcinoma, patients with cervical intraepithelial neoplasia (CIN), patients at high risk of such changes and other groups of patients in whom T-cell function is known to be compromised. Several methods of identifying Langerhans' cells in the cervix were evaluated. However, the indirect immunoperoxidase technique on frozen sections proved optimal since with the range of specific monoclonal available, Langerhans' cells and T-cell subsets could be easily identified in-situ. The simplest method of quantification used a standard length of basement membrane as the denominator (100 basal cells) but counts with computerised image analyser techniques were also used. Good correlation was shown between the Langerhans' cell count per 100 basal cells and the other methods of enumeration investigated. Studies in normal patients showed that Langerhans' cells were a consistent finding in the cervical epithelium of the transformation zone and ectocervix, being present in both areas in similar numbers. Examination showed the majority of the cellular infiltrate in the epithelium and stroma was of T-cell origin. Helper T-cells were shown to predominate in the stroma and cytotoxic T-cells in the epithelium. The image analyser was most useful in quantifying this lymphocytic infiltrate. The T-cell infiltrate was shown to be similar in the ectocervix and transformation zone. A series of 142 patients with CIN were investigated using the same techniques. Internal control biopsies of ectocervix were available for comparison in most instances. Analysis of results showed that two groups were distinguishable, one with concomitant histological features of human papillomavirus infection and the other without. The Langerhans' cells were significantly reduced in the first group and significantly increased in the second compared with the numbers in internal control biopsies. In the lesions showing histological evidence of HPV infection the lymphocytic infiltrate appeared to be influenced by the presence of class II Major Histocompatibility (MHC) antigens on the epithelial cells. The number of helper and cytotoxic T-cells were significantly greater in the epithelium and stroma of MHC class II positive lesions. The percentage composition of the infiltrate was not different comparing the MHC class II positive with the class II negative lesions. (Abstract shortened by ProQuest.)

Newfoundland and Labrador’s Vital Signs: Portrait of a Foundation-University Partnership

Vital Signs, a national program of Community Foundations of Canada, produces annual reports of the same name that examine the quality of life using statistics on fundamental social issues. With these reports, community foundations are able to present a comprehensive and balanced picture of well-being in their communities. The Vital Signs report for Newfoundland and Labrador is produced in partnership between the Community Foundation of Newfoundland and Labrador and the Leslie Harris Centre of Regional Policy and Development, a university research unit with expertise in both promoting community-based research and making academic information accessible to the general public. This article examines the origins of this collaboration and the lessons that have been learned from it, and discusses how the report addresses a need for community knowledge in Newfoundland and Labrador

Imaging Fabry-Perot Spectroscopy of NGC 5775: Kinematics of the Diffuse Ionized Gas Halo

We present imaging Fabry-Perot observations of Halpha emission in the nearly edge-on spiral galaxy NGC 5775. We have derived a rotation curve and a radial density profile along the major axis by examining position-velocity (PV) diagrams from the Fabry-Perot data cube as well as a CO 2-1 data cube from the literature. PV diagrams constructed parallel to the major axis are used to examine changes in azimuthal velocity as a function of height above the midplane. The results of this analysis reveal the presence of a vertical gradient in azimuthal velocity. The magnitude of this gradient is approximately 1 km/s/arcsec, or about 8 km/s/kpc, though a higher value of the gradient may be appropriate in localized regions of the halo. The evidence for an azimuthal velocity gradient is much stronger for the approaching half of the galaxy, although earlier slit spectra are consistent with a gradient on both sides. There is evidence for an outward radial redistribution of gas in the halo. The form of the rotation curve may also change with height, but this is not certain. We compare these results with those of an entirely ballistic model of a disk-halo flow. The model predicts a vertical gradient in azimuthal velocity which is shallower than the observed gradient, indicating that an additional mechanism is required to further slow the rotation speeds in the halo.Comment: 18 pages, 18 figures. Uses emulateapj.cls. Accepted for publication in Ap

A Pair of Compact Red Galaxies at Redshift 2.38, Immersed in a 100 kpc Scale Ly-alpha Nebula

We present Hubble Space Telescope (HST) and ground-based observations of a pair of galaxies at redshift 2.38, which are collectively known as 2142-4420 B1 (Francis et al. 1996). The two galaxies are both luminous extremely red objects (EROs), separated by 0.8 arcsec. They are embedded within a 100 kpc scale diffuse Ly-alpha nebula (or blob) of luminosity ~10^44 erg/s. The radial profiles and colors of both red objects are most naturally explained if they are young elliptical galaxies: the most distant yet found. It is not, however, possible to rule out a model in which they are abnormally compact, extremely dusty starbursting disk galaxies. If they are elliptical galaxies, their stellar populations have inferred masses of ~10^11 solar masses and ages of ~7x10^8 years. Both galaxies have color gradients: their centers are significantly bluer than their outer regions. The surface brightness of both galaxies is roughly an order of magnitude greater than would be predicted by the Kormendy relation. A chain of diffuse star formation extending 1 arcsec from the galaxies may be evidence that they are interacting or merging. The Ly-alpha nebula surrounding the galaxies shows apparent velocity substructure of amplitude ~ 700 km/s. We propose that the Ly-alpha emission from this nebula may be produced by fast shocks, powered either by a galactic superwind or by the release of gravitational potential energy.Comment: 33 pages, 9 figures, ApJ in press (to appear in Jun 10 issue

Galaxy and Mass Assembly (GAMA): ugriz galaxy luminosity functions

Galaxy and Mass Assembly (GAMA) is a project to study galaxy formation and evolution, combining imaging data from ultraviolet to radio with spectroscopic data from the AAOmega spectrograph on the Anglo-Australian Telescope. Using data from Phase 1 of GAMA, taken over three observing seasons, and correcting for various minor sources of incompleteness, we calculate galaxy luminosity functions (LFs) and their evolution in the ugriz passbands. At low redshift, z < 0.1, we find that blue galaxies, defined according to a magnitude-dependent but non-evolving colour cut, are reasonably well fitted over a range of more than 10 magnitudes by simple Schechter functions in all bands. Red galaxies, and the combined blue plus red sample, require double power-law Schechter functions to fit a dip in their LF faintwards of the characteristic magnitude M* before a steepening faint end. This upturn is at least partly due to dust-reddened disc galaxies. We measure the evolution of the galaxy LF over the redshift range 0.002 < z < 0.5 both by using a parametric fit and by measuring binned LFs in redshift slices. The characteristic luminosity L* is found to increase with redshift in all bands, with red galaxies showing stronger luminosity evolution than blue galaxies. The comoving number density of blue galaxies increases with redshift, while that of red galaxies decreases, consistent with prevailing movement from blue cloud to red sequence. As well as being more numerous at higher redshift, blue galaxies also dominate the overall luminosity density beyond redshifts z≃ 0.2. At lower redshifts, the luminosity density is dominated by red galaxies in the riz bands, and by blue galaxies in u and g

Galaxy And Mass Assembly (GAMA): stellar mass estimates

This paper describes the first catalogue of photometrically derived stellar mass estimates for intermediate-redshift (z < 0.65; median z= 0.2) galaxies in the Galaxy And Mass Assembly (GAMA) spectroscopic redshift survey. These masses, as well as the full set of ancillary stellar population parameters, will be made public as part of GAMA data release 2. Although the GAMA database does include near-infrared (NIR) photometry, we show that the quality of our stellar population synthesis fits is significantly poorer when these NIR data are included. Further, for a large fraction of galaxies, the stellar population parameters inferred from the optical-plus-NIR photometry are formally inconsistent with those inferred from the optical data alone. This may indicate problems in our stellar population library, or NIR data issues, or both; these issues will be addressed for future versions of the catalogue. For now, we have chosen to base our stellar mass estimates on optical photometry only. In light of our decision to ignore the available NIR data, we examine how well stellar mass can be constrained based on optical data alone. We use generic properties of stellar population synthesis models to demonstrate that restframe colour alone is in principle a very good estimator of stellar mass-to-light ratio, M*/Li. Further, we use the observed relation between restframe (g-i) and M*/Li for real GAMA galaxies to argue that, modulo uncertainties in the stellar evolution models themselves, (g-i) colour can in practice be used to estimate M*/Li to an accuracy of ≲0.1 dex (1σ). This 'empirically calibrated' (g-i)-M*/Li relation offers a simple and transparent means for estimating galaxies' stellar masses based on minimal data, and so provides a solid basis for other surveys to compare their results to z≲0.4 measurements from GAMA

Wide-field dynamic astronomy in the near-infrared with Palomar Gattini-IR and DREAMS

There have been a dramatic increase in the number of optical and radio transient surveys due to astronomical transients such as gravitational waves and gamma ray bursts, however, there have been a limited number of wide-field infrared surveys due to narrow field-of-view and high cost of infrared cameras, we present two new wide-field near-infrared fully automated surveyors; Palomar Gattini-IR and the Dynamic REd All-sky Monitoring Survey (DREAMS). Palomar Gattini-IR, a 25 square degree J-band imager that begun science operations at Palomar Observatory, USA in October 2018; we report on survey strategy as well as telescope and observatory operations and will also providing initial science results. DREAMS is a 3.75 square degree wide-field imager that is planned for Siding Spring Observatory, Australia; we report on the current optical and mechanical design and plans to achieve on-sky results in 2020. DREAMS is on-track to be one of the first astronomical telescopes to use an Indium Galium Arsenide (InGaAs) detector and we report initial on-sky testing results for the selected detector package. DREAMS is also well placed to take advantage and provide near-infrared follow-up of the LSST