System Architecture and Planetary Obliquity: Implications for Long-term Habitability

In the search for life beyond our solar system, attention should be focused on those planets that have the potential to maintain habitable conditions over the prolonged periods of time needed for the emergence and expansion of life as we know it. The observable planetary architecture is one of the determinants for long-term habitability as it controls the orbital evolution and ultimately the stellar fluxes received by the planet. With an ensemble of n-body simulations and obliquity models of hypothetical planetary systems, we demonstrate that the amplitude and period of the eccentricity, obliquity, and precession cycles of an Earth-like planet are sensitive to the orbital characteristics of a giant companion planet. A series of transient, ocean-coupled climate simulations show how these characteristics of astronomical cycles are decisive for the evolving surface conditions and long-term fractional habitability relative to the modern Earth. The habitability of Earth-like planets increases with the eccentricity of a Jupiter-like companion, provided that the mean obliquity is sufficiently low to maintain temperate temperatures over large parts of its surface throughout the orbital year. A giant companion closer in results in shorter eccentricity cycles of an Earth-like planet but longer, high-amplitude, obliquity cycles. The period and amplitude of obliquity cycles can be estimated to first order from the orbital pathways calculated by the n-body simulations. In the majority of simulations, the obliquity amplitude relates directly to the orbital inclination whereas the period of the obliquity cycle is a function of the nodal precession and the proximity of the giant companion

Biological efficacy of low versus medium dose aspirin after coronary surgery: results from a randomized trial [NCT00262275]

BACKGROUND: The beneficial effect of aspirin after coronary surgery is established; however, a recent study reported the inability of low doses (100 mg) to inhibit postoperative platelet function. We conducted a double-blind randomised trial to establish the efficacy of low dose aspirin and to compare it against medium dose aspirin. METHODS: Patients undergoing coronary surgery were invited to participate and consenting patients were randomised to 100 mg or 325 mg of aspirin daily for 5 days. Our primary outcome was the difference in platelet aggregation (day 5 – baseline) using 1 μg/ml of collagen. Secondary outcomes were differences in EC50 of collagen, ADP and epinephrine (assessed using the technique of Born). RESULTS: From September 2002 to April 2004, 72 patients were randomised; 3 patients discontinued, leaving 35 and 34 in the low and medium dose aspirin arms respectively. The mean aggregation (using 1.1 μg/ml of collagen) was reduced in both the medium and low dose aspirin arms by 37% and 36% respectively. The baseline adjusted difference (low – medium) was 6% (95% CI -3 to 14; p = 0.19). The directions of the results for the differences in EC50 (low – medium) were consistent for collagen, ADP and epinephrine at -0.07 (-0.53 to 0.40), -0.08 (-0.28 to 0.11) and -4.41 (-10.56 to 1.72) respectively, but none were statistically significant. CONCLUSION: Contrary to recent findings, low dose aspirin is effective and medium dose aspirin did not prove superior for inhibiting platelet aggregation after coronary surgery

Quantifying the Influence of Jupiter on the Earth's Orbital Cycles

A wealth of Earth-sized exoplanets will be discovered in the coming years, proving a large pool of candidates from which the targets for the search for life beyond the Solar system will be chosen. The target selection process will require the leveraging of all available information in order to maximise the robustness of the target list and make the most productive use of follow-up resources. Here, we present the results of a suite of $n$-body simulations that demonstrate the degree to which the orbital architecture of the Solar system impacts the variability of Earth's orbital elements. By varying the orbit of Jupiter and keeping the initial orbits of the other planets constant, we demonstrate how subtle changes in Solar system architecture could alter the Earth's orbital evolution -- a key factor in the Milankovitch cycles that alter the amount and distribution of solar insolation, thereby driving periodic climate change on our planet. The amplitudes and frequencies of Earth's modern orbital cycles fall in the middle of the range seen in our runs for all parameters considered -- neither unusually fast nor slow, nor large nor small. This finding runs counter to the `Rare Earth' hypothesis, which suggests that conditions on Earth are so unusual that life elsewhere is essentially impossible. Our results highlight how dynamical simulations of newly discovered exoplanetary systems could be used as an additional means to assess the potential targets of biosignature searches, and thereby help focus the search for life to the most promising targets.Comment: 19 pages; 11 figures; accepted for publication in the Astronomical Journal Version 2 - incorporates typo corrections and minor changes noted at the proofing stage, after acceptanc

Clopidogrel did not inhibit platelet function early after coronary bypass surgery: A prospective randomized trial.

OBJECTIVE: Although the beneficial effect of aspirin prescription after coronary surgery has been established, the efficacy of clopidogrel has never been compared with that of aspirin in the critical early postoperative period. We therefore conducted a prospective, double-blind, randomized controlled trial to compare the efficacies of these antiplatelet regimens. METHODS: Patients undergoing elective primary coronary artery bypass surgery were invited to participate. After the operation, patients were randomized to receive 100 mg aspirin, 325 mg aspirin, or 75 mg clopidogrel tablets daily for 5 days. Our primary outcome measure was platelet aggregation on day 5, expressed as percentage of baseline. Assessment of platelet aggregation was undertaken with the technique of Born. RESULTS: From September 2002 to July 2003, a total of 54 patients were randomized into the study. There were 2 self-withdrawals and 2 protocol violations, leaving 50 patients for analysis, 34 in the aspirin group and 16 in the clopidogrel arm. Compared with baseline, the mean percentage aggregations with collagen on day 5 were 56% for aspirin and 99% for clopidogrel. The mean difference between the two arms was 42% (95% confidence interval 27%-56%) in favor of aspirin. At the same time point, the effective concentration to inhibit 50% aggregation in the samples from patients randomly assigned to receive clopidogrel were not raised for our entire panel of agonists (changes of -0.04 microg/L for collagen, -0.01 micromol/L for epinephrine, and -0.02 micromol/L for adenosine diphosphate). CONCLUSION: Clopidogrel, unlike aspirin, did not inhibit platelet aggregation in the first 5 postoperative days and therefore should not be used as a sole antiplatelet agent early after coronary surgery

EAACI Allergen Immunotherapy User's Guide

Allergen immunotherapy is a cornerstone in the treatment of allergic children. The clinical efficiency relies on a well-defined immunologic mechanism promoting regulatory T cells and downplaying the immune response induced by allergens. Clinical indications have been well documented for respiratory allergy in the presence of rhinitis and/or allergic asthma, to pollens and dust mites. Patients who have had an anaphylactic reaction to hymenoptera venom are also good candidates for allergen immunotherapy. Administration of allergen is currently mostly either by subcutaneous injections or by sublingual administration. Both methods have been extensively studied and have pros and cons. Specifically in children, the choice of the method of administration according to the patient's profile is important. Although allergen immunotherapy is widely used, there is a need for improvement. More particularly, biomarkers for prediction of the success of the treatments are needed. The strength and efficiency of the immune response may also be boosted by the use of better adjuvants. Finally, novel formulations might be more efficient and might improve the patient's adherence to the treatment. This user's guide reviews current knowledge and aims to provide clinical guidance to healthcare professionals taking care of children undergoing allergen immunotherapy.</p

Kaivoskoneiden ohjauskonsolin ja penkkien nostoapuvälineen suunnittelu

Tämän työn tarkoituksena oli suunnitella nostoapuväline helpottamaan Normetin Iisalmen-yksikön ohjaamoiden esivarustelusolussa tapahtuvaa ohjauskonsoleiden ja penkkien asennusta sekä parantamaan työergonomiaa. Työn tavoitteena oli suunnitella mahdollisimman edullinen ja toimiva alle 1000 euron nostoapuväline, joka voidaan CE-merkitä. Tarkoituksena oli tehdä 3D-mallit ja valmistuspiirustukset, jotka työn valmistumisen jälkeen luovutettaisiin Normetille. Työn alussa esiteltiin tuotekehitysprosessin vaiheet ja mitä ne sisältävät, CE-merkintä ja mitä sen saaminen edellyttää sekä nostoapuvälineet ja mitä ne ovat. Tämän jälkeen siirryttiin suunnitteluvaiheeseen, jossa käytiin lävitse luonnosteluvaihetta, itse suunnittelua ja aikaan saatua nostoapuvälinettä sekä FE-analyysiä. Tuloksina saatiin 3D-malli ja valmistuspiirustukset, joiden pohjalta nostoapuväline voidaan valmistaa. Onnistuneesta FE-analyysistä pystyttiin näkemään, missä kohdassa nostoapuvälinettä ovat suurimmat jännityskeskittymät ja toteamaan, että tuotteen rakenne kestää kuorman, joka se on suunniteltu nostamaan. Rakenne kesti jopa kolminkertaisen kuorman nostamisen ilman hajoamista. Hinta-arvio oli erittäin karkea, siinä listatut komponentit ja materiaalit pystyvät vielä muuttumaan sekä niiden hinta vaihdella. Arvion pohjalta voitiin kuitenkin todeta, että tuotteen valmistushinta ilman ruuvitarraimia mitä todennäköisimmin jäi alle 1000 euron, mutta ruuvitarraimien kanssa nostoapuvälineen hinta lähes kaksinkertaistui