Mapping Exoplanets

The varied surfaces and atmospheres of planets make them interesting places to live, explore, and study from afar. Unfortunately, the great distance to exoplanets makes it impossible to resolve their disk with current or near-term technology. It is still possible, however, to deduce spatial inhomogeneities in exoplanets provided that different regions are visible at different times---this can be due to rotation, orbital motion, and occultations by a star, planet, or moon. Astronomers have so far constructed maps of thermal emission and albedo for short period giant planets. These maps constrain atmospheric dynamics and cloud patterns in exotic atmospheres. In the future, exo-cartography could yield surface maps of terrestrial planets, hinting at the geophysical and geochemical processes that shape them.Comment: Updated chapter for Handbook of Exoplanets, eds. Deeg & Belmonte. 17 pages, including 6 figures and 4 pages of reference

Periodic eclipses of the young star PDS 110 discovered with WASP and KELT photometry

We report the discovery of eclipses by circumstellar disc material associated with the young star PDS 110 in the Ori OB1a association using the SuperWASP and Kilodegree Extremely Little Telescope surveys. PDS 110 (HD 290380, IRAS 05209-0107) is a rare Fe/Ge-type star, an similar to 10 Myr-old accreting intermediate-mass star showing strong infrared excess (L-IR/L-bol similar or equal to 0.25). Two extremely similar eclipses with a depth of 30 per cent and duration similar to 25 d were observed in 2008 November and 2011 January. We interpret the eclipses as caused by the same structure with an orbital period of 808 +/- 2 d. Shearing over a single orbit rules out diffuse dust clumps as the cause, favouring the hypothesis of a companion at similar to 2 au. The characteristics of the eclipses are consistent with transits by an unseen low-mass (1.8-70M(Jup)) planet or brown dwarf with a circumsecondary disc of diameter similar to 0.3 au. The next eclipse event is predicted to take place in 2017 September and could be monitored by amateur and professional observatories across the world

The search for transient astrophysical neutrino emission with IceCube-DeepCore

We present the results of a search for astrophysical sources of brief transient neutrino emission using IceCube and DeepCore data acquired between 2012 May 15 and 2013 April 30. While the search methods employed in this analysis are similar to those used in previous IceCube point source searches, the data set being examined consists of a sample of predominantly sub-TeV muon-neutrinos from the Northern Sky (-5 degrees < delta < 90 degrees) obtained through a novel event selection method. This search represents a first attempt by IceCube to identify astrophysical neutrino sources in this relatively unexplored energy range. The reconstructed direction and time of arrival of neutrino events are used to search for any significant self-correlation in the data set. The data revealed no significant source of transient neutrino emission. This result has been used to construct limits at timescales ranging from roughly 1 s to 10 days for generic soft-spectra transients. We also present limits on a specific model of neutrino emission from soft jets in core-collapse supernovae

The Lipid Transfer Protein CERT Interacts with the Chlamydia Inclusion Protein IncD and Participates to ER-Chlamydia Inclusion Membrane Contact Sites

Bacterial pathogens that reside in membrane bound compartment manipulate the host cell machinery to establish and maintain their intracellular niche. The hijacking of inter-organelle vesicular trafficking through the targeting of small GTPases or SNARE proteins has been well established. Here, we show that intracellular pathogens also establish direct membrane contact sites with organelles and exploit non-vesicular transport machinery. We identified the ER-to-Golgi ceramide transfer protein CERT as a host cell factor specifically recruited to the inclusion, a membrane-bound compartment harboring the obligate intracellular pathogen Chlamydia trachomatis. We further showed that CERT recruitment to the inclusion correlated with the recruitment of VAPA/B-positive tubules in close proximity of the inclusion membrane, suggesting that ER-Inclusion membrane contact sites are formed upon C. trachomatis infection. Moreover, we identified the C. trachomatis effector protein IncD as a specific binding partner for CERT. Finally we showed that depletion of either CERT or the VAP proteins impaired bacterial development. We propose that the presence of IncD, CERT, VAPA/B, and potentially additional host and/or bacterial factors, at points of contact between the ER and the inclusion membrane provides a specialized metabolic and/or signaling microenvironment favorable to bacterial development

The effects of ethanol and silymarin treatment during gestation on spatial working memory.

BACKGROUND: Using a rat model we have found that the bioflavonoid silymarin (SY) ameliorates some of the negative consequences of in utero exposure to ethanol (EtOH). In the current study our aim was to determine if spatial working memory (SWM) was impaired in offspring whose mothers were maintained on a liquid diet containing EtOH during different gestational weeks. We also determined if SWM was altered with a concomitant administration of SY with EtOH during specific gestational weeks. METHODS: We provided pregnant Fischer/344 rats with liquid diets containing 35% EtOH derived calories (EDC) during specific weeks of the gestational period. A silymarin/phospholipid compound containing 29.8% silybin co-administered with EtOH was also administered during specific weeks of the gestational period. We tested SWM of the offspring with a radial arm maze on postnatal day (PND) 60. After testing the rats were sacrificed and their brains perfused for later analysis. RESULTS: We observed SWM deficits, as well as a significantly lower brain weight in female offspring born of mothers treated with EtOH during the third week of gestation in comparison to mothers treated during either the first or second weeks of gestation. Rats from any group receiving EtOH in co-administration with SY showed no significant deficits in SWM. CONCLUSION: EtOH treatment during the last week of gestation had the greatest impact on SWM. The addition of SY to the EtOH liquid diet appeared to ameliorate the EtOH-induced learning deficits

Postcopulatory Sexual Selection Is Associated with Reduced Variation in Sperm Morphology

The evolutionary role of postcopulatory sexual selection in shaping male reproductive traits, including sperm morphology, is well documented in several taxa. However, previous studies have focused almost exclusively on the influence of sperm competition on variation among species. In this study we tested the hypothesis that intraspecific variation in sperm morphology is driven by the level of postcopulatory sexual selection in passerine birds.Using two proxy measures of sperm competition level, (i) relative testes size and (ii) extrapair paternity level, we found strong evidence that intermale variation in sperm morphology is negatively associated with the degree of postcopulatory sexual selection, independently of phylogeny.Our results show that the role of postcopulatory sexual selection in the evolution of sperm morphology extends to an intraspecific level, reducing the variation towards what might be a species-specific 'optimum' sperm phenotype. This finding suggests that while postcopulatory selection is generally directional (e.g., favouring longer sperm) across avian species, it also acts as a stabilising evolutionary force within species under intense selection, resulting in reduced variation in sperm morphology traits. We discuss some potential evolutionary mechanisms for this pattern

Childhood tuberculosis is associated with decreased abundance of T cell gene transcripts and impaired T cell function

The WHO estimates around a million children contract tuberculosis (TB) annually with over 80 000 deaths from dissemination of infection outside of the lungs. The insidious onset and association with skin test anergy suggests failure of the immune system to both recognise and respond to infection. To understand the immune mechanisms, we studied genome-wide whole blood RNA expression in children with TB meningitis (TBM). Findings were validated in a second cohort of children with TBM and pulmonary TB (PTB), and functional T-cell responses studied in a third cohort of children with TBM, other extrapulmonary TB (EPTB) and PTB. The predominant RNA transcriptional response in children with TBM was decreased abundance of multiple genes, with 140/204 (68%) of all differentially regulated genes showing reduced abundance compared to healthy controls. Findings were validated in a second cohort with concordance of the direction of differential expression in both TBM (r2 = 0.78 p = 2x10-16) and PTB patients (r2 = 0.71 p = 2x10-16) when compared to a second group of healthy controls. Although the direction of expression of these significant genes was similar in the PTB patients, the magnitude of differential transcript abundance was less in PTB than in TBM. The majority of genes were involved in activation of leucocytes (p = 2.67E-11) and T-cell receptor signalling (p = 6.56E-07). Less abundant gene expression in immune cells was associated with a functional defect in T-cell proliferation that recovered after full TB treatment (p<0.0003). Multiple genes involved in T-cell activation show decreased abundance in children with acute TB, who also have impaired functional T-cell responses. Our data suggest that childhood TB is associated with an acquired immune defect, potentially resulting in failure to contain the pathogen. Elucidation of the mechanism causing the immune paresis may identify new treatment and prevention strategies

Mimotopes selected with a neutralizing antibody against urease B from Helicobacter pylori induce enzyme inhibitory antibodies in mice upon vaccination

<p>Abstract</p> <p>Background</p> <p>Urease B is an important virulence factor that is required for <it>Helicobacter pylori </it>to colonise the gastric mucosa. Mouse monoclonal antibodies (mAbs) that inhibit urease B enzymatic activity will be useful as vaccines for the prevention and treatment of <it>H. pylori </it>infection. Here, we produced murine mAbs against urease B that neutralize the enzyme's activity. We mapped their epitopes by phage display libraries and investigated the immunogenicity of the selected mimotopes <it>in vivo</it>.</p> <p>Results</p> <p>The urease B gene was obtained (GenBank accession No. <ext-link ext-link-id="DQ141576" ext-link-type="gen">DQ141576</ext-link>) and the recombinant pGEX-4T-1/UreaseB protein was expressed in <it>Escherichia coli </it>as a 92-kDa recombinant fusion protein with glutathione-S-transferase (GST). Five mAbs U001-U005 were produced by a hybridoma-based technique with urease B-GST as an immunogen. Only U001 could inhibit urease B enzymatic activity. Immunoscreening via phage display libraries revealed two different mimotopes of urease B protein; EXXXHDM from ph.D.12-library and EXXXHSM from ph.D.C7C that matched the urease B proteins at 347-353 aa. The antiserum induced by selected phage clones clearly recognised the urease B protein and inhibited its enzymatic activity, which indicated that the phagotope-induced immune responses were antigen specific.</p> <p>Conclusions</p> <p>The present work demonstrated that phage-displayed mimotopes were accessible to the mouse immune system and triggered a humoral response. The urease B mimotope could provide a novel and promising approach for the development of a vaccine for the diagnosis and treatment of <it>H. pylori </it>infection.</p

Models of care for musculoskeletal health: A cross-sectional qualitative study of Australian stakeholders' perspectives on relevance and standardised evaluation

Background: The prevalence and impact of musculoskeletal conditions are predicted to rapidly escalate in the coming decades. Effective strategies are required to minimise 'evidence-practice', 'burden-policy' and 'burden-service' gaps and optimise health system responsiveness for sustainable, best-practice healthcare. One mechanism by which evidence can be translated into practice and policy is through Models of Care (MoCs), which provide a blueprint for health services planning and delivery. While evidence supports the effectiveness of musculoskeletal MoCs for improving health outcomes and system efficiencies, no standardised national approach to evaluation in terms of their 'readiness' for implementation and 'success' after implementation, is yet available. Further, the value assigned to MoCs by end users is uncertain. This qualitative study aimed to explore end users' views on the relevance of musculoskeletal MoCs to their work and value of a standardised evaluation approach. Methods: A cross-sectional qualitative study was undertaken. Subject matter experts (SMEs) with health, policy and administration and consumer backgrounds were drawn from three Australian states. A semi-structured interview schedule was developed and piloted to explore perceptions about musculoskeletal MoCs including: i) aspects important to their work (or life, for consumers) ii) usefulness of standardised evaluation frameworks to judge 'readiness' and 'success' and iii) challenges associated with standardised evaluation. Verbatim transcripts were analysed by two researchers using a grounded theory approach to derive key themes. Results: Twenty-seven SMEs (n = 19; 70.4 % female) including five (18.5 %) consumers participated in the study. MoCs were perceived as critical for influencing and initiating changes to best-practice healthcare planning and delivery and providing practical guidance on how to implement and evaluate services. A 'readiness' evaluation framework assessing whether critical components across the health system had been considered prior to implementation was strongly supported, while 'success' was perceived as an already familiar evaluation concept. Perceived challenges associated with standardised evaluation included identifying, defining and measuring key 'readiness' and 'success' indicators; impacts of systems and context changes; cost; meaningful stakeholder consultation and developing a widely applicable framework. Conclusions: A standardised evaluation framework that includes a strong focus on 'readiness' is important to ensure successful and sustainable implementation of musculoskeletal MoCs

Milk exosomes: beyond dietary microRNAs

Extracellular vesicles deliver a variety of cargos to recipient cells, including the delivery of cargos in dietary vesicles from bovine milk to non-bovine species. The rate of discovery in this important line of research is slowed by a controversy whether the delivery and bioactivity of a single class of vesicle cargos, microRNAs, are real or not. This opinion paper argues that the evidence in support of the bioavailability of microRNAs encapsulated in dietary exosomes outweighs the evidence produced by scholars doubting that phenomenon is real. Importantly, this paper posits that the time is ripe to look beyond microRNA cargos and pursue innovative pathways through which dietary exosomes alter metabolism. Here, we highlight potentially fruitful lines of exploration