First Half Of Year Research Articles

Fragmentation Analysis of Cosmos 2421 Satellite

2008年上半年俄罗斯的Cosmos 2421卫星接连发生了三次不同程度的解体, 并产生了数百颗碎片. 本文利用美国公布的Cosmos 2421卫星及其碎片的两行根数系列, 对三次解体事件发生的时间, 解体碎片的轨道分布、速度分布和面积质量比以及寿命等进行了分析, 并对解体碎片对航天器的影响进行了评估. 分析结果表明, Cosmos2421卫星的三次解体事件分别发生在2008年3月14日、4月28日、6月9日; 解体碎片分布在200~1400 km 的高度范围内; Cosmos 2421卫星解体导致的碎片在空间三个方向上的速度增量均值分别为-8.4m/s, 8.6m/s, -8.3m/s; 67\%的解体碎片的寿命都在1年以内, 解体事件造成500 km以下的空间碎片空间密度增加, 对载人航天器产生了影响. 通过对Cosmos 2421卫星解体事件的分析可以看出, 利用解体碎片的轨道信息可以反演解体事件特性, 根据解体碎片的寿命和空间密度分布的计算结果可以评估解体事件对未来发射活动和在轨卫星的影响.

Comparative use of perioperative chemotherapy (CT) in non-small cell lung cancer (NSCLC) between 2004 and 2007

7564 Background: Adjuvant (ADJ) platinum-based CT has become a new standard of care for patients (pts) with resected stage II and III NSCLC, and is discussed in selected stage IB pts. Impact of positive randomized trials which showed significant survival improvement (first published in 2004) on the use of ADJ CT has been poorly studied to date. Methods: A retrospective study of consecutive pts with NSCLC who underwent curative surgery during the first half of year 2004 and 2007 in the surgical center Marie Lannelongue (France) was conducted. Logistic regression models were employed to identify cofactors associated with the use of ADJ CT (excluding stage IV). Odds ratio (OR) > 1 corresponds to a more frequent use than in reference group. Results: A total of 240 pts (116 in 2004, 124 in 2007) underwent curative surgery for NSCLC (11% IA; 30% IB; 27% II; 27% III; 5% IV). Among all pts, 12 % received neoADJ CT (less in 2007, 8% vs 16% p=.04), 35% ADJ (4% both). Reasons for not receiving ADJ CT included stage I (34%), death (11%), comorbidities (10%), poor performance status (10%), advanced age (8%), post-operative complications (7%), patient refusal (3%). More ADJ CT was prescribed in 2007 (41% vs 30% in 2004, p=.009). Overall, 45% of pts with stage II-III received ADJ CT in 2004 versus 69% did so in 2007. In multivariate analysis (194 pts), ADJ CT was associated with the year of inclusion (OR=2.67 p=.009), stage (stage II, OR=6.77, stage III, OR=16.85; p<.0001), serious medical history (OR=.41 p=.01) and salvage surgery (OR=.26 p=.03). Cisplatin was the preferred platinum compound in 76% of neoADJ regimens (mostly cisplatin-docetaxel), and 70% of ADJ CT (mostly cisplatin-vinorelbine). Conclusions: The presentation and publication of “positive” ADJ CT trials had significantly increased prescription of ADJ CT in pts with stage II-III NSCLC. Nevertheless 31% of the stage II-III did not received CT mostly because of comorbidities, highlighting the need of a personalized CT. No significant financial relationships to disclose.

The trigger system of the ALICE muon spectrometer at the LHC

The ALICE experiment aims at investigating the properties of strongly interacting matter at the extreme energy density reached in heavy ion collisions at the LHC. The trigger system of the muon spectrometer consists in four planes of Resistive Plate Chamber (RPC) detectors operated in streamer mode, 21 k front-end channels and fast-decision electronics, covering an area of 140 m 2. It is designed to reconstruct (muon) tracks, in a large background environment, to provide a fast trigger signal. Indeed, a trigger decision is delivered each 25 ns (40 MHz) with a total latency of 800 ns. The hit position on the RPC is measured in two orthogonal directions with an accuracy of about 1 cm. Selected aspects of the Muon Trigger design will be described. The performances, of both detectors and electronics, measured with dedicated test tools and cosmic rays during the commissioning runs carried out in the first half of year 2008 will be reported.

Latitude and local time dependence of ULF wave power at the magnetopause: A Cluster–Double Star study

Strong ULF wave activity has been observed at magnetopause crossings over a long time. Those turbulent like waves are possibly one of the contributors to particle penetration from the solar wind to the magnetosphere through the magnetopause. Spatio Temporal Analysis of Field Fluctuations wave experiments onboard Cluster and Double Star TC1 spacecraft permit the comparison of those waves during quasi‐simultaneous magnetopause crossings, some being at the same local time but at different latitude, the TC1 Double Star orbit being nearly equatorial and the Cluster orbit being polar. From a survey of the first half of year 2004 and beginning of 2005 data, 23 coordinated magnetopause crossings have been identified, out of which 11 are at the same local time, for which the wave power density has been calculated. No clear dependence in local time has been found; in particular, the wave power density is not stronger at noon in the vicinity of the subsolar point than at other local times, the morning hour data showing more dispersed values than afternoon ones. For most of the events occurring at the same local time, the wave power density measured by Double Star (at low latitude) is stronger than the one measured by the Cluster spacecraft (at much higher latitude). If those first results were to be confirmed, it could imply a predominant role of the equatorial plane in the solar wind/ magnetosphere coupling via ULF wave turbulence, with no preference for the subsolar region.

The Fund's Income Position for FY 2009-Midyear Review

This paper reviews the outlook for the Fund’s income position for the financial year 2009 taking into account developments through the first half of the year. The FY 2009 income outlook has improved, mainly as a result of new lending activity associated with the turmoil in global financial markets, together, to a lesser extent, with stronger-than-projected returns in the Investment Account (IA) in the first half of the financial year. The updated projections indicate that the net income position would be slightly positive in FY 2009. However, the actual outcome remains subject to considerable uncertainty related to the timing and amounts of disbursements under current arrangements, as well as potential new arrangements and the performance of the IA

Utilization Pattern of Antibiotics in Different Wards of Specialized Sari Emam University Hospital in Iran

The main goal of this study was to compare the utilization of antibiotics in different wards of a university hospital. Consumption of antibacterial drugs rose dramatically during years 2000-2005 in Iran. Data collected during first half of year 2000 and 2005 in Emam University Hospital in city of Sari in Iran, showed use of antibiotics jumped from 95.4 DBDs (Defined Daily Doses per patient's bed-days) to 124 DBDs. Distribution of different class of anti-microbial showed highest increase in use of vancomycin with 28.4 folds and clindamycin with 4.8 fold. Use of cotrimoxazole, aminoglycosides and tetracyclines remained fairly unchanged during this period. However, during the same period, consumption of penicillin G, aminopenicillins and cloxacillin dropped 10.3, 3.8 and 3 fold, respectively. Among university hospital departments, oncology ward followed by ICU and general surgery consumed the most antibacterial agents in year 2000. In year 2005, ICU ward followed by gynecology, oncology and orthopedic were among the University Hospital Departments with highest consumption of antibiotics. The most highly used antibiotics in year 2000 were cefazolin followed by ampicillin, ceftizoxime and gentamicin. In year 2005, cefazolin, ceftriaoxone, gentamicin and ciprofloxacin were the most prescribed antibiotics. Injectable antibiotics accounted for 51.8 and 79.4% of total DBDs in first half of years 2000 and 2005, respectively. The bulk of prescription (90% of total DBDs) was made up of 13 out of 32 total antibiotic types in 2000 and 11 out of 29 total antibiotics types in 2005. Comparing with similar hospitals in other countries, data presented show a dramatic increase in antibiotics prescribed by physician in Emam University Hospital.

STUDY ON THE PARTICLE INJECTIONS DURING HILDCAA INTERVALS

The relation between substorm occurrences and HILDCAA events has been an issue. We have studied the association of particle injections with substorm onsets during HILDCAA intervals for the first half of year 2003. The examination of aurora images observed by IMAGE spacecraft and electron flux data measured by LANL satellites exhibits a close association of repetitive particle injections with substorm activity. We also find that HILDCAA events can occur equally frequently during slow speed solar wind streams as long as the interplanetary magnetic field exhibits Alfvenic wave feature.

Safety issues on laser megajoule facility

The Laser Megajoule (LMJ) is a facility dedicated to inertial confinement fusion experiments. Building construction phase should start in the first half of year 2003. Use of a deuterium–tritium mixture in the experiments and high neutron yield generation induces hazards such as contamination of equipments inside the target chamber and activation of materials. Calculations have been undertaken to estimate dose rates levels in the facility. Optimization is under development on ALARA principle basis to reduce activation and workers exposure. Decontamination is an other important safety issue for LMJ; different processes are available and have to be considered (lasers, foams …). Radioactive wastes will be generated and their disposal has to be taken into account.

Pricing Cac 40 Index Options with Stochastic Volatility

The failure of the Black-Scholes (1973) model is now well documented in the literature. In this article, we discuss two alternative option valuation models whose volatility follows a stochastic process. Namely, the Heston (1993) closed-form solution model and the Hull and White (1988) model in a series expansion form, both allowing for arbitrary correlation between increments. The empirical study is carried out on French PXL European call options written on the CAC 40 index during the first half of year 2001. This paper fulfills the lack of option pricing empirical studies devoted to the French market. We discuss calibration of the models and results obtained from the out-of-sample pricing using analysis in cross-section. We also discuss the empirical dynamic of the skew. We found that misprising was globally deacreasing with maturity and increasing with low strike prices. We find that the Heston (1993) model was more likely to capture the changes in the implied volatility regime in that it can allows smile patterns to transform into skew patterns while the Hull and White (1988) model allows only for changes in the skew slope sign. We explain to what extent this phenomenon is linked with the values of some of the structural parameters.

A decrease from 8 to 6 weeks in obstetrics and gynecology clerkship: Effect on medical students' cognitive knowledge

We undertook this study to determine whether a decrease in the amount of time a third-year medical student spent in an obstetrics and gynecology clerkship would cause a decrease in the knowledge of the subject. We compared National Board of Medical Examiners (NBME) obstetrics and gynecology subject examination scores of 168 students at the University of Texas Medical Branch at Galveston completing an 8-week obstetrics and gynecology rotation or the 1989-1990 academic year to scores of 187 University of Texas Medical Branch students competing a 6-week rotation during 1990-1991. No significant change in the total mean NBME subject examination score in obstetrics and gynecology was noted after the decrease in rotation length. Passing scores were those greater than 445 points. The failure rate for those students who completed the 8-week rotation was consistent throughout the 1989-1990 academic year. In contrast, those students who rotated through obstetrics and gynecology during the 6-week clerkship in the first half of the academic year had a failure rate that was statistically higher than those taking the clerkship in the last half of the year. The length of the obstetrics and gynecology clerkship was shortened to 6 weeks without significantly affecting students' overall performance on the NBME obstetrics and gynecology subject examination. However, a greater percentage of students who completed the rotation during the first half of the year scored low on the NBME obstetrics and gynecology subject examination than did those taking the rotation and thus the NBME subject examination in the second half of the year.

Appraisal

The recession in the UK is coming to an end, with a gradual recovery expected in the second half of the year. It now seems that stocks of goods and materials were run down sharply in the first half of the year. This is a common occurrence at the low point of the economic cycle, leading to a spontaneous upturn once the stock adjustment is complete.This time the recovery is being helped by a rise in exports. Looking ahead to the first half of next year we expect the recovery to be reinforced by renewed growth in consumer spending, but we may have to wait rather longer for fixed investment to pick up as well.

Economic Growth under Retrenchment—A Report on the Analysis of the Microeconomic Situation in the First Half of 1986

The background of this report is the economic expansion in the first half of last year [1985] and the retrenchment in the first half of this year [1986]. By comparing the behavior of enterprises under different economic environments, the report draws a descriptive conclusion in regard to the quantitative and qualitative duality that is expressed by our country's enterprises following the upsurge and subsequent decline of the economy. This report demonstrates that changes in the micromechanism of the economy cause fundamental changes in the nature and shape of enterprise growth, and thereby proposes a strategy for dealing with and ameliorating the impact of the decline of economic efficiency.

Chapter I. The Home Economy

Comparing the first half of this year with the first half of 1987, domestic demand rose very rapidly, probably by about 8 per cent. Consumer spending, after accelerating for some years, had reached a rate of growth of around 6 per cent. This was now reinforced by a sharp rise in expenditure on fixed investment, which may have been about 10 per cent over this period. This surge in demand was met by a good response from domestic supply, gross domestic product rising by about 5 per cent. But at the same time the boom conditions contributed to a significant deterioration in the balance of payments. A small surplus on current account in the first half of last year has been turned into a deficit at an annual rate of about £11 billion.

Death Rate Lowest on Record during First Half of Year

Death Rate Lowest on Record during First Half of Year