An Investigation into the Protein Composition of the Teneral Glossina morsitans morsitans Peritrophic Matrix.

BACKGROUND Tsetse flies serve as biological vectors for several species of African trypanosomes. In order to survive, proliferate and establish a midgut infection, trypanosomes must cross the tsetse fly peritrophic matrix (PM), which is an acellular gut lining surrounding the blood meal. Crossing of this multi-layered structure occurs at least twice during parasite migration and development, but the mechanism of how trypanosomes do so is not understood. In order to better comprehend the molecular events surrounding trypanosome penetration of the tsetse PM, a mass spectrometry-based approach was applied to investigate the PM protein composition using Glossina morsitans morsitans as a model organism. METHODS PMs from male teneral (young, unfed) flies were dissected, solubilised in urea/SDS buffer and the proteins precipitated with cold acetone/TCA. The PM proteins were either subjected to an in-solution tryptic digestion or fractionated on 1D SDS-PAGE, and the resulting bands digested using trypsin. The tryptic fragments from both preparations were purified and analysed by LC-MS/MS. RESULTS Overall, nearly 300 proteins were identified from both analyses, several of those containing signature Chitin Binding Domains (CBD), including novel peritrophins and peritrophin-like glycoproteins, which are essential in maintaining PM architecture and may act as trypanosome adhesins. Furthermore, 27 proteins from the tsetse secondary endosymbiont, Sodalis glossinidius, were also identified, suggesting this bacterium is probably in close association with the tsetse PM. CONCLUSION To our knowledge this is the first report on the protein composition of teneral G. m. morsitans, an important vector of African trypanosomes. Further functional analyses of these proteins will lead to a better understanding of the tsetse physiology and may help identify potential molecular targets to block trypanosome development within the tsetse

ACCESS III: The Nature of Star Formation in the Shapley Supercluster

We present a joint analysis of panoramic Spitzer/MIPS mid-infrared and GALEX ultraviolet imaging of the Shapley supercluster at z=0.048. Combining this with spectra of 814 supercluster members and 1.4GHz radio continuum maps, this represents the largest complete census of star-formation (both obscured and unobscured) in local cluster galaxies to date, reaching SFRs~0.02Msun/yr. We take advantage of this comprehensive panchromatic dataset to perform a detailed analysis of the nature of star formation in cluster galaxies, using several quite independent diagnostics of the quantity and intensity of star formation to develop a coherent view of the types of star formation within cluster galaxies. We observe a robust bimodality in the infrared (f_24/f_K) galaxy colours, which we are able to identify as another manifestation of the broad split into star-forming spiral and passive elliptical galaxy populations seen in UV-optical surveys. This diagnostic also allows the identification of galaxies in the process of having their star formation quenched as the infrared analogue to the UV "green valley" population. The bulk of supercluster galaxies on the star-forming sequence have specific-SFRs consistent with local field specific-SFR-M* relations, and form a tight FIR-radio correlation confirming that their FIR emission is due to star formation. We show that 85% of the global SFR is quiescent star formation within spiral disks, as manifest by the observed sequence in the IRX-beta relation being significantly offset from the starburst relation of Kong et al. (2004), while their FIR-radio colours indicate dust heated by low-intensity star formation. Just 15% of the global SFR is due to nuclear starbursts. The vast majority of star formation seen in cluster galaxies comes from normal infalling spirals who have yet to be affected by the cluster environment.Comment: 17 pages, 9 figures. Accepted for publication in MNRA

Constraining the ages of the fireballs in the wake of the dIrr galaxy VCC1217 / IC3418

A complex of Halpha emitting blobs with strong FUV excess is associated to the dIrr galaxy VCC1217 / IC3418 (Hester et al. 2010), and extends up to 17 Kpc in the South-East direction. These outstanding features can be morphologically divided into diffuse filaments and compact knots, where most of the star formation activity traced by Halpha takes place. We investigate the properties of the galaxy and the blobs using a multiwavelength approach in order to constrain their origin. We collect publicly available data in UV and Halpha and observe the scene in the optical U,g,r,i bands with LBT. The photometric data allows to evaluate the star formation rate and to perform a SED fitting separately of the galaxy and the blobs in order to constrain their stellar population age. Moreover we analyze the color and luminosity profile of the galaxy and its spectrum to investigate its recent interaction with the Virgo cluster. Our analysis confirms that the most plausible mechanism for the formation of the blobs is ram pressure stripping by the Virgo cluster IGM. The galaxy colors, luminosity profile and SED are consistent with a sudden gas depletion in the last few hundred Myr. The SED fitting of the blobs constrains their ages in < 400 Myr.Comment: 10 pages, 11 figures, accepted for publication in Astronomy and Astrophysic

Detecting mirror matter on Earth via its thermal imprint on ordinary matter

Mirror matter type dark matter can exist on the Earth's surface, potentially in enhanced concentrations at various anomalous impact sites. Mirror matter fragments can draw in heat from the ordinary matter environment, radiate mirror photons and thereby cool the surrounding ordinary matter. We quantify this effect and suggest that it could be used to help locate mirror matter deposits. This method, together with the centrifuge technique, seems to provide the most promising means to experimentally detect mirror matter type dark matter in the Earth.Comment: 9 page

Reducing falls after hospital discharge: Protocol for a randomised controlled trial evaluating an individualised multi-modal falls education program for older adults

Introduction: Older adults frequently fall after discharge from hospital. Older people may have low self-perceived risk of falls and poor knowledge about falls prevention. The primary aim of the study is to evaluate the effect of providing tailored falls prevention education in addition to usual care on falls rates in older people after discharge from hospital compared to providing a social intervention in addition to usual care. Methods and analyses: The ‘Back to My Best’ study is a multisite, single blind, parallel-group randomised controlled trial with blinded outcome assessment and intention-to-treat analysis, adhering to CONSORT guidelines. Patients (n=390) (aged 60 years or older; score more than 7/10 on the Abbreviated Mental Test Score; discharged to community settings) from aged care rehabilitation wards in three hospitals will be recruited and randomly assigned to one of two groups. Participants allocated to the control group shall receive usual care plus a social visit. Participants allocated to the experimental group shall receive usual care and a falls prevention programme incorporating a video, workbook and individualised follow-up from an expert health professional to foster capability and motivation to engage in falls prevention strategies. The primary outcome is falls rates in the first 6 months after discharge, analysed using negative binomial regression with adjustment for participant\u27s length of observation in the study. Secondary outcomes are injurious falls rates, the proportion of people who become fallers, functional status and health-related quality of life. Healthcare resource use will be captured from four sources for 6 months after discharge. The study is powered to detect a 30% relative reduction in the rate of falls (negative binomial incidence ratio 0.70) for a control rate of 0.80 falls per person over 6 months. Ethics and dissemination: Results will be presented in peer-reviewed journals and at conferences worldwide. This study is approved by hospital and university Human Research Ethics Committees

Variant antigen repertoires in Trypanosoma congolense populations and experimental infections can be profiled from deep sequence data using universal protein motifs

African trypanosomes are vector-borne hemoparasites of humans and animals. In the mammal, parasites evade the immune response through antigenic variation. Periodic switching of the Variant Surface Glycoprotein (VSG) coat covering their cell surface allows sequential expansion of serologically distinct parasite clones. Trypanosome genomes contain many hundreds of VSG genes, subject to rapid changes in nucleotide sequence, copy number and chromosomal position. Thus, analysing, or even quantifying, VSG diversity over space and time presents an enormous challenge to conventional techniques. Indeed, previous population genomic studies have overlooked this vital aspect of pathogen biology for lack of analytical tools. Here we present a method for analysing population-scale VSG diversity in Trypanosoma congolense from deep sequencing data. Previously, we suggested that T. congolense VSG segregate into defined 'phylotypes' that do not recombine. In our dataset comprising 41 T. congolense genome sequences from across Africa, these phylotypes are universal and exhaustive. Screening sequence contigs with diagnostic protein motifs accurately quantifies relative phylotype frequencies, providing a metric of VSG diversity, called the 'Variant Antigen Profile'. We applied our metric to VSG expression in the tsetse fly, showing that certain, rare VSG phylotypes may be preferentially expressed in infective, metacyclic-stage parasites. Hence, variant antigen profiling accurately and rapidly determines VSG gene and transcript repertoire from sequence data, without need for manual curation or highly contiguous sequences. It offers a tractable approach to measuring VSG diversity across strains and during infections, which is imperative to understanding the host-parasite interaction at population and individual scales. [Abstract copyright: Published by Cold Spring Harbor Laboratory Press.

An insight into the sialome of Glossina morsitans morsitans

<p>Abstract</p> <p>Background</p> <p>Blood feeding evolved independently in worms, arthropods and mammals. Among the adaptations to this peculiar diet, these animals developed an armament of salivary molecules that disarm their host's anti-bleeding defenses (hemostasis), inflammatory and immune reactions. Recent sialotranscriptome analyses (from the Greek <it>sialo </it>= saliva) of blood feeding insects and ticks have revealed that the saliva contains hundreds of polypeptides, many unique to their genus or family. Adult tsetse flies feed exclusively on vertebrate blood and are important vectors of human and animal diseases. Thus far, only limited information exists regarding the Glossina sialome, or any other fly belonging to the Hippoboscidae.</p> <p>Results</p> <p>As part of the effort to sequence the genome of <it>Glossina morsitans morsitans</it>, several organ specific, high quality normalized cDNA libraries have been constructed, from which over 20,000 ESTs from an adult salivary gland library were sequenced. These ESTs have been assembled using previously described ESTs from the fat body and midgut libraries of the same fly, thus totaling 62,251 ESTs, which have been assembled into 16,743 clusters (8,506 of which had one or more EST from the salivary gland library). Coding sequences were obtained for 2,509 novel proteins, 1,792 of which had at least one EST expressed in the salivary glands. Despite library normalization, 59 transcripts were overrepresented in the salivary library indicating high levels of expression. This work presents a detailed analysis of the salivary protein families identified. Protein expression was confirmed by 2D gel electrophoresis, enzymatic digestion and mass spectrometry. Concurrently, an initial attempt to determine the immunogenic properties of selected salivary proteins was undertaken.</p> <p>Conclusions</p> <p>The sialome of <it>G. m. morsitans </it>contains over 250 proteins that are possibly associated with blood feeding. This set includes alleles of previously described gene products, reveals new evidence that several salivary proteins are multigenic and identifies at least seven new polypeptide families unique to <it>Glossina</it>. Most of these proteins have no known function and thus, provide a discovery platform for the identification of novel pharmacologically active compounds, innovative vector-based vaccine targets, and immunological markers of vector exposure.</p

Comparing and contrasting the νμ→ντ\nu_{\mu} \to \nu_{\tau} and νμ→νs\nu_{\mu} \to \nu_s solutions to the atmospheric neutrino problem with SuperKamiokande data

The $\nu_{\mu} \to \nu_{\tau}$ and $\nu_{\mu} \to \nu_s$ solutions to the atmospheric neutrino problem are compared with SuperKamiokande data. The differences between these solutions due to matter effects in the Earth are calculated for the ratio of $\mu$-like to $e$-like events and for up-down flux asymmetries. These quantities are chosen because they are relatively insensitive to theoretical uncertainties in the overall neutrino flux normalisation and detection cross-sections and efficiencies. A $\chi^2$ analysis using these quantities is performed yielding $3\sigma$ ranges which are approximately given by $(0.725 - 1.0, 4 \times 10^{-4} - 2 \times 10^{-2} eV^2)$ and $(0.74 - 1.0, 1 \times 10^{-3} - 2 \times 10^{-2} eV^2)$ for $(\sin^2 2\theta,\Delta m^2)$ for the $\nu_{\mu} \to \nu_{\tau}$ and $\nu_{\mu} \to \nu_s$ solutions, respectively. Values of $\Delta m^2$ smaller than about $2 \times 10^{-3}$ eV$^2$ are disfavoured for the $\nu_{\mu} \to \nu_s$ solution, suggesting that future long baseline experiments should see a positive signal if this scenario is the correct one.Comment: revtex, 22 pages, 12 figure