Capability of a space-based space surveillance system to detect and track objects in GEO, MEO and LEO orbits

In this paper we present the results from the coverage and the orbit determination accuracy simulations performed within the recently completed ESA study “Assessment Study for Space Based Space Surveillance (SBSS) Demonstration System” (Airbus Defence and Space consortium). This study consisted in investigating the capability of a space based optical sensor (SBSS) orbiting in low Earth orbit (LEO) to detect and track objects in GEO (geosynchronous orbit), MEO (medium Earth orbit) and LEO and to determinate and improve initial orbits from such observations. Space based systems may achieve better observation conditions than ground based sensors in terms of astrometric accuracy, detection coverage, and timeliness. The primary observation mode of the proposed SBSS demonstrator is GEO surveillance, i.e. the systematic search and detection of unknown and known objects. GEO orbits are specific and unique orbits from dynamical point of view. A space-based sensor may scan the whole GEO ring within one sidereal day if the orbit and pointing directions are chosen properly. For an efficient survey, our goal was to develop a leak-proof GEO fence strategy. Collaterally, we show that also MEO, LEO and other (GTO,Molniya, etc.) objects would be possible to observe by the system and for a considerable number of LEO objects to down to size of 1 cm we can obtain meaningful statistical data for improvement and validation of space debris environment models

Beta-alanine supplementation improves jumping power and affects severe-intensity performance in professional alpine skiers.

INTRODUCTION Supplementation with beta-alanine may have positive effects on severe-intensity, intermittent, and isometric strength-endurance performance. These could be advantageous for competitive alpine skiers, whose races last 45 to 150 s, require metabolic power above the aerobic maximum, and involve isometric muscle work. Further, beta-alanine supplementation affects the muscle force-frequency relationship, which could influence explosiveness. We explored the effects of beta-alanine on explosive jump performance, severe exercise energy metabolism, and severe-intensity ski-like performance. METHODS Nine male elite alpine skiers consumed 4.8 g/d beta-alanine or placebo for 5 weeks in a double-blind fashion. Before and after, they performed countermovement jumps (CMJ), a 90-s cycling bout at 110% VO2max (CLT), and a maximal 90-s box jump test (BJ90). RESULTS Beta-alanine improved maximal (+7 ± 3%, d = 0.9) and mean CMJ power (+7 ± 2%, d = 0.7), tended to reduce oxygen deficit (-3 ± 8%, p = .06) and lactate accumulation (-12 ± 31%) and enhance aerobic energy contribution (+1.3 ± 2.9%, p = .07) in the CLT, and improved performance in the last third of BJ90 (+7 ± 4%, p = .02). These effects were not observed with placebo. CONCLUSIONS Beta-alanine supplementation improved explosive and repeated jump performance in elite alpine skiers. Enhanced muscle contractility could possibly explain improved explosive and repeated jump performance. Increased aerobic energy production could possibly help explain repeated jump performance as well.

Predictors of thromboprophylaxis in hospitalised medical patients. Explicit ASsessment of Thromboembolic RIsk and Prophylaxis for Medical PATients in SwitzErland (ESTIMATE).

Both, underuse and overuse of thromboprophylaxis in hospitalised medical patients is common. We aimed to explore clinical factors associated with the use of pharmacological or mechanical thromboprophylaxis in acutely ill medical patients at high (Geneva Risk Score ≥ 3 points) vs low (Geneva Risk Score < 3 points) risk of venous thromboembolism. Overall, 1,478 hospitalised medical patients from eight large Swiss hospitals were enrolled in the prospective Explicit ASsessment of Thromboembolic RIsk and Prophylaxis for Medical PATients in SwitzErland (ESTIMATE) cohort study. The study is registered on ClinicalTrials.gov, number NCT01277536. Thromboprophylaxis increased stepwise with increasing Geneva Risk Score (p< 0.001). Among the 962 high-risk patients, 366 (38 %) received no thromboprophylaxis; cancer-associated thrombocytopenia (OR 4.78, 95 % CI 2.75-8.31, p< 0.001), active bleeding on admission (OR 2.88, 95 % CI 1.69-4.92, p< 0.001), and thrombocytopenia without cancer (OR 2.54, 95 % CI 1.31-4.95, p=0.006) were independently associated with the absence of prophylaxis. The use of thromboprophylaxis declined with increasing severity of thrombocytopenia (p=0.001). Among the 516 low-risk patients, 245 (48 %) received thromboprophylaxis; none of the investigated clinical factors predicted its use. In conclusion, in acutely ill medical patients, bleeding and thrombocytopenia were the most important factors for the absence of thromboprophylaxis among high-risk patients. The use of thromboprophylaxis among low-risk patients was inconsistent, without clearly identifiable predictors, and should be addressed in further research.

Implicit motives and basic need satisfaction in extreme endurance sports.

Previous research has shown that the effects of basic psychological needs on the flow experience in sports are moderated by implicit motives. However, so far, only leisure and health-oriented sports have been analyzed. In a pilot study and a main study (N = 29, 93), we tested whether the implicit achievement and affiliation motives interact with the need for competence and the need for social relatedness satisfaction, respectively, to predict flow experience and well-being in extreme endurance athletes. Results showed that highly achievement-motivated individuals benefited more from the need for competence satisfaction in terms of flow than individuals with a low achievement motive did. In addition, highly affiliation-motivated individuals whose need for social relatedness is satisfied reported higher positive affect and lower exercise addiction scores than athletes with a low motive. We discuss the differential effects of the interplay between the achievement and affiliation motives and basic needs on different outcome variables.

Atherogenic dyslipidemia and residual cardiovascular risk in statin-treated patients

BACKGROUND AND PURPOSE Treatment with statins reduces the rate of cardiovascular events in high-risk patients, but residual risk persists. At least part of that risk may be attributable to atherogenic dyslipidemia characterized by low high-density lipoprotein cholesterol (≤40 mg/dL) and high triglycerides (triglycerides≥150 mg/dL). METHODS We studied subjects with stroke or transient ischemic attack in the Prevention of Cerebrovascular and Cardiovascular Events of Ischemic Origin With Terutroban in Patients With a History of Ischemic Stroke or Transient Ischemic Attack (PERFORM; n=19,100) and Stroke Prevention by Aggressive Reduction in Cholesterol Levels (SPARCL; n=4731) trials who were treated with a statin and who had high-density lipoprotein cholesterol and triglycerides measurements 3 months after randomization (n=10,498 and 2900, respectively). The primary outcome measure for this exploratory analysis was the occurrence of major cardiovascular events (nonfatal myocardial infarction, nonfatal stroke, or cardiovascular death). We also performed a time-varying analysis to account for all available high-density lipoprotein cholesterol and triglyceride measurements. RESULTS A total of 10% of subjects in PERFORM and 9% in SPARCL had atherogenic dyslipidemia after ≥3 months on start statin therapy. After a follow-up of 2.3 years (PERFORM) and 4.9 years (SPARCL), a major cardiovascular event occurred in 1123 and 485 patients in the 2 trials, respectively. The risk of major cardiovascular events was higher in subjects with versus those without atherogenic dyslipidemia in both PERFORM (hazard ratio, 1.36; 95% confidence interval, 1.14-1.63) and SPARCL (hazard ratio, 1.40; 95% confidence interval, 1.06-1.85). The association was attenuated after multivariable adjustment (hazard ratio, 1.23; 95% confidence interval, 1.03-1.48 in PERFORM and hazard ratio, 1.24; 95% confidence interval, 0.93-1.65 in SPARCL). Time-varying analysis confirmed these findings. CONCLUSIONS The presence of atherogenic dyslipidemia was associated with higher residual cardiovascular risk in PERFORM and SPARCL subjects with stroke or transient ischemic attack receiving statin therapy. Specific therapeutic interventions should now be trialed to address this residual risk.

The effect of ego depletion on sprint start reaction time

In the current study, we consider that optimal sprint start performance requires the self-control of responses. Therefore, start performance should depend on athletes' self-control strength. We assumed that momentary depletion of self-control strength (ego depletion) would either speed up or slow down the initiation of a sprint start, where an initiation that was sped up would carry the increased risk of a false start. Applying a mixed between- (depletion vs. nondepletion) and within- (before vs. after manipulation of depletion) subjects design, we tested the start reaction times of 37 sport students. We found that participants' start reaction times decelerated after finishing a depleting task, whereas it remained constant in the nondepletion condition. These results indicate that sprint start performance can be impaired by unrelated preceding actions that lower momentary self-control strength. We discuss practical implications in terms of optimizing sprint starts and related overall sprint performance.

Sex-related differences in access to care among patients with premature acute coronary syndrome

BACKGROUND Access to care may be implicated in disparities between men and women in death after acute coronary syndrome, especially among younger adults. We aimed to assess sex-related differences in access to care among patients with premature acute coronary syndrome and to identify clinical and gender-related determinants of access to care. METHODS We studied 1123 patients (18-55 yr) admitted to hospital for acute coronary syndrome and enrolled in the GENESIS-PRAXY cohort study. Outcome measures were door-to-electrocardiography, door-to-needle and door-to-balloon times, as well as proportions of patients undergoing cardiac catheterization, reperfusion or nonprimary percutaneous coronary intervention. We performed univariable and multivariable logistic regression analyses to identify clinical and gender-related determinants of timely procedures and use of invasive procedures. RESULTS Women were less likely than men to receive care within benchmark times for electrocardiography (≤ 10 min: 29% v. 38%, p = 0.02) or fibrinolysis (≤ 30 min: 32% v. 57%, p = 0.01). Women with ST-segment elevation myocardial infarction (MI) were less likely than men to undergo reperfusion therapy (primary percutaneous coronary intervention or fibrinolysis) (83% v. 91%, p = 0.01), and women with non-ST-segment elevation MI or unstable angina were less likely to undergo nonprimary percutaneous coronary intervention (48% v. 66%, p < 0.001). Clinical determinants of poorer access to care included anxiety, increased number of risk factors and absence of chest pain. Gender-related determinants included feminine traits of personality and responsibility for housework. INTERPRETATION Among younger adults with acute coronary syndrome, women and men had different access to care. Moreover, fewer than half of men and women with ST-segment elevation MI received timely primary coronary intervention. Our results also highlight that men and women with no chest pain and those with anxiety, several traditional risk factors and feminine personality traits were at particularly increased risk of poorer access to care.

Safety and efficacy of imatinib in CML over a period of 10 years: data from the randomized CML-study IV.

Tyrosine kinase inhibitors (TKI) have changed the natural course of chronic myeloid leukemia (CML). With the advent of second-generation TKI safety and efficacy issues have gained interest. The randomized CML - Study IV was used for a long-term evaluation of imatinib (IM). 1503 patients have received IM, 1379 IM monotherapy. After a median observation of 7.1 years, 965 patients (64%) still received IM. At 10 years, progression-free survival was 82%, overall survival 84%, 59% achieved MR(5), 72% MR(4.5), 81% MR(4), 89% major molecular remission and 92% MR(2) (molecular equivalent to complete cytogenetic remission). All response levels were reached faster with IM800 mg except MR(5). Eight-year probabilities of adverse drug reactions (ADR) were 76%, of grades 3-4 22%, of non-hematologic 73%, and of hematologic 28%. More ADR were observed with IM800 mg and IM400 mg plus interferon α (IFN). Most patients had their first ADR early with decreasing frequency later on. No new late toxicity was observed. ADR to IM are frequent, but mostly mild and manageable, also with IM 800 mg and IM 400 mg+IFN. The deep molecular response rates indicate that most patients are candidates for IM discontinuation. After 10 years, IM continues to be an excellent initial choice for most patients with CML.Leukemia advance online publication, 13 March 2015; doi:10.1038/leu.2015.36.

Effects of dark chocolate consumption on the prothrombotic response to acute psychosocial stress in healthy men

Flavanoid-rich dark chocolate consumption benefits cardiovascular health, but underlying mechanisms are elusive. We investigated the acute effect of dark chocolate on the reactivity of prothrombotic measures to psychosocial stress. Healthy men aged 20-50 years (mean ± SD: 35.7 ± 8.8) were assigned to a single serving of either 50 g of flavonoid-rich dark chocolate (n=31) or 50 g of optically identical flavonoid-free placebo chocolate (n=34). Two hours after chocolate consumption, both groups underwent an acute standardised psychosocial stress task combining public speaking and mental arithmetic. We determined plasma levels of four stress-responsive prothrombotic measures (i. e., fibrinogen, clotting factor VIII activity, von Willebrand Factor antigen, fibrin D-dimer) prior to chocolate consumption, immediately before and after stress, and at 10 minutes and 20 minutes after stress cessation. We also measured the flavonoid epicatechin, and the catecholamines epinephrine and norepinephrine in plasma. The dark chocolate group showed a significantly attenuated stress reactivity of the hypercoagulability marker D-dimer (F=3.87, p=0.017) relative to the placebo chocolate group. Moreover, the blunted D-dimer stress reactivity related to higher plasma levels of the flavonoid epicatechin assessed before stress (F=3.32, p = 0.031) but not to stress-induced changes in catecholamines (p's=0.35). There were no significant group differences in the other coagulation measures (p's≥0.87). Adjustments for covariates did not alter these findings. In conclusion, our findings indicate that a single consumption of flavonoid-rich dark chocolate blunted the acute prothrombotic response to psychosocial stress, thereby perhaps mitigating the risk of acute coronary syndromes triggered by emotional stress.

Ego depletion and attention regulation under pressure: Is a temporary loss of self-control strength indeed related to impaired attention regulation?

In the current study we investigated whether ego depletion negatively affects attention regulation under pressure in sports by assessing participants' dart throwing performance and accompanying gaze behavior. According to the strength model of self-control, the most important aspect of self-control is attention regulation. Because higher levels of state anxiety are associated with impaired attention regulation, we chose a mixed design with ego depletion (yes vs. no) as between-subjects and anxiety level (high vs. low) as within-subjects factor. Participants performed a perceptual-motor task requiring selective attention, namely, dart throwing. In line with our expectations, depleted participants in the high-anxiety condition performed worse and displayed a shorter final fixation on bull's eye, demonstrating that when one's self-control strength is depleted, attention regulation under pressure cannot be maintained. This is the first study that directly supports the general assumption that ego depletion is a major factor in influencing attention regulation under pressure.

Corneal Cross-Linking in a 4-Year-Old Child With Keratoconus and Down Syndrome

PURPOSE To describe the clinical outcome of corneal cross-linking (CXL) in a young child with keratoconus. METHODS This is a case report of a young girl with keratoconus with ophthalmologic findings and 3-year follow-up. Follow-up visits included visual acuity measurement, retinoscopy, corneal tomography, and topography. RESULTS A girl with Down syndrome was diagnosed with bilateral keratoconus and relative amblyopia at the age of 4 years. The best-corrected near visual acuity was 20/100 binocularly. Corneal tomography showed the following parameters: OD K(max) 47.2 diopters (D), thinnest location 442 μm; OS K(max) 49.6 D, thinnest location 432 μm. Three months later, the keratoconus in the left eye progressed (K(max) 50.2 D, thinnest location 424 μm), and CXL was performed. One year later, CXL was necessary also in the right eye because of progression. The girl was most recently reexamined at the age of 7 years. The corrected near visual acuity was 20/80 in both eyes. The corneal curvature slightly flattened, and the corneal thickness stabilized (OD K(max) 46.8 D, thinnest location 389 μm; OS K(max) 49.4 D, thinnest location 360 μm). CONCLUSIONS Onset of keratoconus can occur in early childhood, especially in patients with Down syndrome. In this case, CXL was performed at 4 and 5 years of age without complications and stopped further keratoconus progression.

The Dark Side of the Moon: Meta-analytical Impact of Recruitment Strategies on Risk Enrichment in the Clinical High Risk State for Psychosis

Background: The individual risk of developing psychosis after being tested for clinical high-risk (CHR) criteria (posttest risk of psychosis) depends on the underlying risk of the disease of the population from which the person is selected (pretest risk of psychosis), and thus on recruitment strategies. Yet, the impact of recruitment strategies on pretest risk of psychosis is unknown. Methods: Meta-analysis of the pretest risk of psychosis in help-seeking patients selected to undergo CHR assessment: total transitions to psychosis over the pool of patients assessed for potential risk and deemed at risk (CHR+) or not at risk (CHR−). Recruitment strategies (number of outreach activities per study, main target of outreach campaign, and proportion of self-referrals) were the moderators examined in meta-regressions. Results: 11 independent studies met the inclusion criteria, for a total of 2519 (CHR+: n = 1359; CHR−: n = 1160) help-seeking patients undergoing CHR assessment (mean follow-up: 38 months). The overall meta-analytical pretest risk for psychosis in help-seeking patients was 15%, with high heterogeneity (95% CI: 9%–24%, I 2 = 96, P < .001). Recruitment strategies were heterogeneous and opportunistic. Heterogeneity was largely explained by intensive (n = 11, β = −.166, Q = 9.441, P = .002) outreach campaigns primarily targeting the general public (n = 11, β = −1.15, Q = 21.35, P < .001) along with higher proportions of self-referrals (n = 10, β = −.029, Q = 4.262, P = .039), which diluted pretest risk for psychosis in patients undergoing CHR assessment. Conclusions: There is meta-analytical evidence for overall risk enrichment (pretest risk for psychosis at 38monhts = 15%) in help-seeking samples selected for CHR assessment as compared to the general population (pretest risk of psychosis at 38monhts=0.1%). Intensive outreach campaigns predominantly targeting the general population and a higher proportion of self-referrals diluted the pretest risk for psychosis.

Get real in individual participant data (IPD) meta-analysis: a review of the methodology.

Individual participant data (IPD) meta-analysis is an increasingly used approach for synthesizing and investigating treatment effect estimates. Over the past few years, numerous methods for conducting an IPD meta-analysis (IPD-MA) have been proposed, often making different assumptions and modeling choices while addressing a similar research question. We conducted a literature review to provide an overview of methods for performing an IPD-MA using evidence from clinical trials or non-randomized studies when investigating treatment efficacy. With this review, we aim to assist researchers in choosing the appropriate methods and provide recommendations on their implementation when planning and conducting an IPD-MA. © 2015 The Authors. Research Synthesis Methods published by John Wiley & Sons, Ltd.