30 research outputs found

    A chemical survey of exoplanets with ARIEL

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    Thousands of exoplanets have now been discovered with a huge range of masses, sizes and orbits: from rocky Earth-like planets to large gas giants grazing the surface of their host star. However, the essential nature of these exoplanets remains largely mysterious: there is no known, discernible pattern linking the presence, size, or orbital parameters of a planet to the nature of its parent star. We have little idea whether the chemistry of a planet is linked to its formation environment, or whether the type of host star drives the physics and chemistry of the planet’s birth, and evolution. ARIEL was conceived to observe a large number (~1000) of transiting planets for statistical understanding, including gas giants, Neptunes, super-Earths and Earth-size planets around a range of host star types using transit spectroscopy in the 1.25–7.8 μm spectral range and multiple narrow-band photometry in the optical. ARIEL will focus on warm and hot planets to take advantage of their well-mixed atmospheres which should show minimal condensation and sequestration of high-Z materials compared to their colder Solar System siblings. Said warm and hot atmospheres are expected to be more representative of the planetary bulk composition. Observations of these warm/hot exoplanets, and in particular of their elemental composition (especially C, O, N, S, Si), will allow the understanding of the early stages of planetary and atmospheric formation during the nebular phase and the following few million years. ARIEL will thus provide a representative picture of the chemical nature of the exoplanets and relate this directly to the type and chemical environment of the host star. ARIEL is designed as a dedicated survey mission for combined-light spectroscopy, capable of observing a large and well-defined planet sample within its 4-year mission lifetime. Transit, eclipse and phase-curve spectroscopy methods, whereby the signal from the star and planet are differentiated using knowledge of the planetary ephemerides, allow us to measure atmospheric signals from the planet at levels of 10–100 part per million (ppm) relative to the star and, given the bright nature of targets, also allows more sophisticated techniques, such as eclipse mapping, to give a deeper insight into the nature of the atmosphere. These types of observations require a stable payload and satellite platform with broad, instantaneous wavelength coverage to detect many molecular species, probe the thermal structure, identify clouds and monitor the stellar activity. The wavelength range proposed covers all the expected major atmospheric gases from e.g. H2O, CO2, CH4 NH3, HCN, H2S through to the more exotic metallic compounds, such as TiO, VO, and condensed species. Simulations of ARIEL performance in conducting exoplanet surveys have been performed – using conservative estimates of mission performance and a full model of all significant noise sources in the measurement – using a list of potential ARIEL targets that incorporates the latest available exoplanet statistics. The conclusion at the end of the Phase A study, is that ARIEL – in line with the stated mission objectives – will be able to observe about 1000 exoplanets depending on the details of the adopted survey strategy, thus confirming the feasibility of the main science objectives.Peer reviewedFinal Published versio

    Altered Immune Responses in Rhesus Macaques Co-Infected with SIV and Plasmodium cynomolgi: An Animal Model for Coincident AIDS and Relapsing Malaria

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    BACKGROUND:Dual epidemics of the malaria parasite Plasmodium and HIV-1 in sub-Saharan Africa and Asia present a significant risk for co-infection in these overlapping endemic regions. Recent studies of HIV/Plasmodium falciparum co-infection have reported significant interactions of these pathogens, including more rapid CD4+ T cell loss, increased viral load, increased immunosuppression, and increased episodes of clinical malaria. Here, we describe a novel rhesus macaque model for co-infection that supports and expands upon findings in human co-infection studies and can be used to identify interactions between these two pathogens. METHODOLOGY/PRINCIPAL FINDINGS:Five rhesus macaques were infected with P. cynomolgi and, following three parasite relapses, with SIV. Compared to macaques infected with SIV alone, co-infected animals had, as a group, decreased survival time and more rapid declines in markers for SIV progression, including peripheral CD4+ T cells and CD4+/CD8+ T cell ratios. The naïve CD4+ T cell pool of the co-infected animals was depleted more rapidly than animals infected with SIV alone. The co-infected animals also failed to generate proliferative responses to parasitemia by CD4+ and CD8+ T cells as well as B cells while also having a less robust anti-parasite and altered anti-SIV antibody response. CONCLUSIONS/SIGNIFICANCE:These data suggest that infection with both SIV and Plasmodium enhances SIV-induced disease progression and impairs the anti-Plasmodium immune response. These data support findings in HIV/Plasmodium co-infection studies. This animal model can be used to further define impacts of lentivirus and Plasmodium co-infection and guide public health and therapeutic interventions

    Coaching as a social process

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    In this conceptual paper, we argue the importance to the coaching profession of a critical understanding of coaching as a social process, in order to promote coaching as an enabler for change, and facilitate its use in other cultures and challenging contexts. We start with a critical analysis of the origin of coaching, arguing that neoliberal values have been embedded in the discourse of coaching. We also discuss the impact of coaching as an instrumental and ideological device, sometimes used in organisations as a process of control, and suggest that understanding coaching as a social process has the potential to transform it into an enabler for change. We propose a framework for understanding how different philosophical positions affect the way coaches may respond to the challenges of intercultural or oppressive social contexts. We conclude with a discussion of the implications for coaching research and development

    Per- and poly-fluoroalkyl substances (PFASs) in follicular fluid from women experiencing infertility in Australia

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    Per- and poly-fluoroalkyl substances (PFASs) have been widely used and detected in human matrices. Evidence that PFAS exposure may be associated with adverse human reproductive health effects exists, however, data is limited. The use of a human matrix such as follicular fluid to determine chemical exposure, along with reproductive data will be used to investigate if there is a relationship between PFAS exposure and human fertility. Objective: This study aims to: (1) assess if associations exist between PFAS concentrations and/or age and fertilisation rate (as determined in follicular fluid of women in Australia who received assisted reproductive treatment (ART)); and (2) assess if associations exist between PFAS concentrations and infertility aetiology. Methods: Follicular fluids were originally collected from participants who underwent fully stimulated ART treatment cycles at an in vitro fertilisation (IVF) clinic in the period 2006–2009 and 2010–11 in Queensland, Australia. The samples were available for analysis of 32 PFASs including perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA), perfluorohexane sulfonate (PFHxS), and perfluorononanoic acid (PFNA) using high performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS). 97 samples were matched with limited demographic data (age and fertilisation rate) and five infertility factors (three known female factors): 1) endometriosis, 2) polycystic ovarian syndrome (PCOS), and 3) genital tract infections - tubal/pelvic inflammation disease; as well as 4) male factor, and 5) idiopathic or unknown from either males or females. SPSS was used for linear regression analysis. Results: PFASs were detected in all follicular fluid samples with the mean concentrations of PFOS and PFOA, 4.9, and 2.4 ng/ml, respectively. A lower fertilisation rate was observed at higher age when age was added as a covariate, but there was no relationship between PFAS concentrations and fertilisation rate. There were few statistically significant associations between PFAS concentrations in follicular fluid and infertility factors. Log-transformed PFHxS concentrations were lower in females with endometriosis (factor 1) than in women who had reported ‘male factors’ as a reason of infertility, while PFHpA was higher in women who had infertile due to female factors (factor 1–3) compared to those who had infertile due to male factor. Conclusion: PFASs were detected in follicular fluid of Australian women who had been treated at an IVF clinic. PFAS exposure found in follicular fluids is linked to increased risk of some infertility factors, and increased age was associated with decreased fertilisation rate in our data. But there was no relationship between PFAS and ferlitisation rate. Further large-scale investigations of PFAS and health effects including infertility are warranted

    Effect of gravity and microgravity on intracranial pressure

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    Da bi međuljudski privatni i poslovni odnosi bili uspješni, komunikacija je ključan faktor. Ona je, po definiciji, razmjena informacija, ideja i osjećaja verbalnim i neverbalnim sredstvima, a proizlazi iz komunikacijskih potreba sudionika. Za učinkovitost elementa komunikacije bitna je vještina govora i pisanja, a upravo se zbog toga učinkovitost komunikacije izjednačuje s verbalnim sposobnostima pojedinca. Osobna funkcija komunikacije te međusobna funkcija najvažnije su kada je u pitanju poslovna komunikacija, a njene osnovne komponente su poznavanje jezika, interakcijske vještine, te kulturno znanje. Pošiljatelj poruke nastoji biti uvjerljiv, a to će postići primjenom stručnog znanja posjedujući ekspertnu i referentnu moć. Kao što znamo, u velikoj većini slučajeva najvažniji je način na koji pričamo o određenoj temi, a nužno je znati način na koji zaintrigirati sudionika razgovora. Dogovoreni književni standard u govoru i pisanju prije svega nas osposobljava da se u istom kulturološko-nacionalnom krugu bolje razumijemo, da naša poruka bude jasna i učinkovitija, a kroz sve to da zadovoljava općeprihvaćene norme lijepoga. Takav način komunikacije štedi vrijeme, utječe na potencijalne korisnike usluga, klijente, stranke i sl.For succesful interpersonal and business relationship, communication is a key factor. It's defined as an exchange of information, ideas and feelings by verbal and non-verbal means, and arises from the communication needs of the participants. Personal function and mutual function are the most important when it comes to business comunication, and that's why communication efficiency can be the same as an individual's verbal ability. Basic components are cultural knowledge and language skills. The sender of the message tries to be convincing, and this could be achieved through the application of expertise, possessing expert and referential power. In most of the cases, the most important thing is how we talk about particular topic, and it's essential to know how to intrigue a participant in a conversation. The same standard in writing and speech, the same cultural circle can make us understand each other better, and this will make our message clear and effective, as it should be. This way of communication saves time, affects on potential service users, clients, parties, etc

    Effect of gravity and microgravity on intracranial pressure

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    KEY POINTS: Astronauts have recently been discovered to have impaired vision, with a presentation that resembles syndromes of elevated intracranial pressure on Earth. Gravity has a profound effect on fluid distribution and pressure within the human circulation. In contrast to prevailing theory, we observed that microgravity reduces central venous and intracranial pressure. This being said, intracranial pressure is not reduced to the levels observed in the 90 deg seated upright posture on Earth. Thus, over 24 h in zero gravity, pressure in the brain is slightly above that observed on Earth, which may explain remodelling of the eye in astronauts. ABSTRACT: Astronauts have recently been discovered to have impaired vision, with a presentation that resembles syndromes of elevated intracranial pressure (ICP). This syndrome is considered the most mission-critical medical problem identified in the past decade of manned spaceflight. We recruited five men and three women who had an Ommaya reservoir inserted for the delivery of prophylactic CNS chemotherapy, but were free of their malignant disease for at least 1 year. ICP was assessed by placing a fluid-filled 25 gauge butterfly needle into the Ommaya reservoir. Subjects were studied in the upright and supine position, during acute zero gravity (parabolic flight) and prolonged simulated microgravity (6 deg head-down tilt bedrest). ICP was lower when seated in the 90 deg upright posture compared to lying supine (seated, 4 ± 1 vs. supine, 15 ± 2 mmHg). Whilst lying in the supine posture, central venous pressure (supine, 7 ± 3 vs. microgravity, 4 ± 2 mmHg) and ICP (supine, 17 ± 2 vs. microgravity, 13 ± 2 mmHg) were reduced in acute zero gravity, although not to the levels observed in the 90 deg seated upright posture on Earth. Prolonged periods of simulated microgravity did not cause progressive elevations in ICP (supine, 15 ± 2 vs. 24 h head-down tilt, 15 ± 4 mmHg). Complete removal of gravity does not pathologically elevate ICP but does prevent the normal lowering of ICP when upright. These findings suggest the human brain is protected by the daily circadian cycles in regional ICPs, without which pathology may occur

    Developing a Deep Brain Stimulation Neuromodulation Network for Parkinson Disease, Essential Tremor, and Dystonia: Report of a Quality Improvement Project

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    <div><p>Objective</p><p>To develop a process to improve patient outcomes from deep brain stimulation (DBS) surgery for Parkinson disease (PD), essential tremor (ET), and dystonia.</p><p>Methods</p><p>We employed standard quality improvement methodology using the Plan-Do-Study-Act process to improve patient selection, surgical DBS lead implantation, postoperative programming, and ongoing assessment of patient outcomes.</p><p>Results</p><p>The result of this quality improvement process was the development of a neuromodulation network. The key aspect of this program is rigorous patient assessment of both motor and non-motor outcomes tracked longitudinally using a REDCap database. We describe how this information is used to identify problems and to initiate Plan-Do-Study-Act cycles to address them. Preliminary outcomes data is presented for the cohort of PD and ET patients who have received surgery since the creation of the neuromodulation network.</p><p>Conclusions</p><p>Careful outcomes tracking is essential to ensure quality in a complex therapeutic endeavor like DBS surgery for movement disorders. The REDCap database system is well suited to store outcomes data for the purpose of ongoing quality assurance monitoring.</p></div
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