Fast optical Layer mesh protection using pre-cross-connected trails

Conventional optical networks are based on SONET rings, but since rings are known to use bandwidth inefficiently, there has been much research into shared mesh protection, which promises significant bandwidth savings. Unfortunately, most shared mesh protection schemes cannot guarantee that failed traffic will be restored within the 50-ms timeframe that SONET standards specify. A notable exception is the p-cycle scheme of Grover and Stamatelakis. We argue, however, that p-cycles have certain limitations, e.g., there is no easy way to adapt p-cycles to a path-based protection scheme, and p-cycles seem more suited to static traffic than to dynamic traffic. In this paper we show that the key to fast restoration times is not a ring-like topology per se, but rather the ability to pre-cross-connect protection paths. This leads to the concept of a pre-cross-connected trail or PXT, which is a structure that is more flexible than rings and that adapts readily to both path-based and link-based schemes and to both static and dynamic traffic. The PXT protection scheme achieves fast restoration speeds, and our simulations, which have been carefully chosen using ideas from experimental design theory, show that the bandwidth efficiency of the PXT protection scheme is comparable to that of conventional shared mesh protection schemes.     

Enhanced detectability of small objects in correlated clutter usingan improved 2-D adaptive lattice algorithm

Two-dimensional (2-D) adaptive filtering is a technique that can be applied to many image processing applications. This paper will focus on the development of an improved 2-D adaptive lattice algorithm (2-D AL) and its application to the removal of correlated clutter to enhance the detectability of small objects in images. The two improvements proposed here are increased flexibility in the calculation of the reflection coefficients and a 2-D method to update the correlations used in the 2-D AL algorithm. The 2-D AL algorithm is shown to predict correlated clutter in image data and the resulting filter is compared with an ideal Wiener-Hopf filter. The results of the clutter removal will be compared to previously published ones for a 2-D least mean square (LMS) algorithm. 2-D AL is better able to predict spatially varying clutter than the 2-D LMS algorithm, since it converges faster to new image properties. Examples of these improvements are shown for a spatially varying 2-D sinusoid in white noise and simulated clouds. The 2-D LMS and 2-D AL algorithms are also shown to enhance a mammogram image for the detection of small microcalcifications and stellate lesions.     

Platelet-aggregation inhibition and hemodynamic effects of beraprost sodium, a new oral prostacyclin derivative: a study in healthy male subjects

The antiaggregation and hemodynamic effects of the new prostacyclin analogue beraprost sodium were investigated in a randomized, placebo-controlled, double-blind clinical trial of Latin-square design. Twelve healthy Caucasian males randomly received 8-day oral treatments of 20, 40, and 60 micrograms of beraprost sodium and a placebo. One-week washout periods followed each treatment. Pharmacokinetic and pharmacodynamic measurements were performed on days 1 and 8 for each period of treatment. All three doses of beraprost sodium significantly inhibited platelet aggregation on day 8 (compared with placebo) during the 1st h after drug intake. Incubation of the 60-micrograms beraprost sodium samples with ADP (2, 5, and 10 microM) and collagen (1.25 micrograms/mL) decreased platelet aggregation by 10, 19, 16, and 6 +/- 4% (mean +/- SE), respectively, compared with placebo. No significant hemodynamic effects on blood pressure, heart rate, and digital pulse were observed. The 60-micrograms dose of beraprost sodium did significantly decrease the IRZ index (which may reflect the left ventricular pre-ejection period) on days 1 and 8. Some subjects experienced headache and facial flushing, effects that were dose dependent and reversible. Beraprost sodium at 20- to 60-micrograms doses exerts platelet antiaggregation (day 8 of therapy) and slight hemodynamic (days 1 and 8 of treatment) effects in Caucasian males. Beraprost sodium hemodynamic effects and potential benefits in patients with cardiovascular disease should be explored further.     

Increased thrombosis incidence in a family with an inherited protein S deficiency and a high oxygen affinity hemoglobin variant

Inherited protein S deficiency and the presence of a rare high oxygen affinity hemoglobin variant: Hb Rainier [beta 145 (HC2) Tyr-->Cys] were found in a family. Among 16 studied members, nine were found as carriers of protein S deficiency (type I with decrease of total, free, and activity levels). Six subjects carried the high-affinity hemoglobin variant, which displayed an increase of blood viscosity. Four members combined both abnormalities. Three had thrombotic accidents before the age of 30. We suggest the combination of protein S deficiency and the presence of this hemoglobin variant can lead to a severe primary hypercoagulable state with pathological consequences compared to each genetic defect alone.     

Association of dysfibrinogenemia and thrombosis. Apropos of a family (Fibrinogen Melun) and review of the literature

We report a family with history of deep and superficial venous thrombosis. A large number of siblings had numerous episodes of deep venous thrombosis and less frequently arterial thrombosis. The most frequent site was lower limb. Dysfibrinogenaemia seems to play an essential role in predisposition to thromboembolism in this family, other known aetiologies having been excluded. Genetic studies of fibrinogen gene show a point mutation in the gamma chain (364 Asp-Val), the site close to gamma 363 one of the sites involved in fibrin monomers polymerisation, although fibrinogen polymerisation is normal. Review of the 250 families with dysfibrinogenaemia published up to now shows that the prevalence of dysfibrinogenaemia in patients with a history of thromboembolism is about 0.7%, and that thrombosis is observed in about 10% of cases of dysfibrinogenaemia. Abortion risk seems to be increased in women with dysfibrinogenaemia. In contrast thromboembolism risk does not seem to be higher during pregnancy, but may be increased after delivery. The main mechanisms which have been proposed to explain thromboembolism observed in dysfibrinogenaemia are: resistance of the clot to thrombolysis; defective thrombin binding; enhanced platelet aggregation; increased blood viscosity, alteration of clot architecture. This family study together with the previously reported cases supports the hypothesis that there is a link between thrombosis and dysfibrinogenaemia in a small number of patients.     

The Australian Vietnam Veterans Health Study: II. self-reported health of veterans compared with the Australian population

BACKGROUND: Self-reported physical health status of Australian Vietnam veterans was determined 20-25 years after the war and its relation to combat was investigated. METHOD: An epidemiological cohort study of a simple random sample of Army veterans posted to Vietnam between 1964 and 1972 was conducted with personal interviews using the Australian Bureau of Statistics Health Interview Survey questionnaire to compare veterans with the Australian population and a 21-item combat exposure index used to measure the relationship of combat to physical health. RESULTS: Veterans reported greater health service usage and more recent health actions than population expectations. They also reported excess health problems in almost all recent illness disease categories except endocrine conditions and cardiovascular conditions; only 6 of 37 chronic disease groups were not elevated compared to the population. Adjustment for non-response changed estimates only slightly. Combat exposure was significantly related to reports of recent and chronic mental disorders, recent hernia and chronic ulcer, recent eczema and chronic rash, deafness, chronic infective and parasitic disease, chronic back disorders and symptoms, signs and ill-defined conditions. CONCLUSION: Combat exposure may have significantly increased reports of only some health problems. A general position to complain as a result of psychological conditions due to combat is not consistent with the lack of relationship between combat and reports of physical conditions.     

Cdk1 is a marker of proliferation in human lymphoid cells

To better understand the relationship between the proliferation of human lymphoid cells and the expression of cdk1, a catalytic subunit of the histone H1 kinase (H1K), we examined its mRNA and protein content in 3 B-cell lines: Ramos, Reh-6 and IARC 963. Cells were elutriated according to their position in the cell cycle. Cell fractions were analyzed for cdk1 mRNA and protein cellular content by Northern blot and immunoblot, respectively, as well as for H1K activity. Both mRNA and protein amounts and H1K activity varied according to cell cycle phase, the lowest values being observed in G1-enriched fractions. For comparison, elutriated fractions were also tested for the expression of cdk2 and cdk4 proteins. Both showed some variations among fractions, but they were less clear than those of cdk1. We also tested 29 samples of lymphoid neoplastic and non-neoplastic tissues for proliferative activity (percentage of S and G2/M cells estimated by flow cytometry) and expression of cdk1, cdk2 and cdk4 proteins. We found a significant correlation between the percentage of cells in S or S + G2/M phases and cdk1 protein content but not cdk2 or cdk4 content. We conclude that cdk1 expression in human lymphoid cells varies during the cell cycle at both mRNA and protein levels.     

The effect of recombinant factor VIIa (NovoSeven) in healthy volunteers receiving acenocoumarol to an International Normalized Ratio above 2.0

Vitamin K antagonists are most commonly used in long-term thrombosis prophylaxis and the use in patients with cardiovascular disease seems to be increasing. By interfering with the normal hemostatic mechanism, an increased risk of bleeding will arise and administration of human plasma or prothrombin complex concentrates may be necessary. It can be difficult to normalize hemostasis using plasma and prothrombin complex concentrates, because these may be associated with thromboembolic side-effects. The level of factor VII, one of the vitamin-K-dependent coagulation factors, decreases during oral anticoagulant therapy and the administration of recombinant factor VIIa normalizes the prolonged prothrombin time in warfarin-treated rats. After administration of acenocoumarol (International Normalized Ratio > 2), decreased levels of factor X and factor IX (19-46%), protein C (2-20%) and factor VII (4-17%) were found in 28 healthy volunteers. After one dose of recombinant factor VIIa (5, 10, 20, 40, 80, 120, 160, 240, or 320 microg/kg) the International Normalized Ratio and prothrombin time normalized, which may imply an effect on bleeding in individuals receiving oral anticoagulant therapy. The lowest dose (5 microg/kg) normalized the International Normalized Ratio for 12 h and doses > 120 microg/kg normalized it for 24 h. Fragment 1+2 stayed within its normal range in all dose groups, indicating that no systemic coagulation occurred.     

Phase I study of interleukin-6 in children with solid tumours in relapse

The aim of this study was to evaluate the feasibility, toxicity and efficacy of escalating doses of subcutaneous recombinant interleukin-6 (IL-6) in children with solid tumours in relapse. Recombinant IL-6 was administered subcutaneously once daily for 14 consecutive days, with a 14 day follow-up period. The starting dose for IL-6 was 1 microgram/kg/day and was escalated in subsequent patients groups until 10 micrograms/kg. Doses were escalated every 3 patients, provided that grade III or IV organ toxicity did not occur at the preceding dose level. Twelve patients were treated, three at each dose level. No grade 3-4 major organ toxicity was observed. Flu-like symptoms and fatigue were the most common side effects. All these symptoms resolved after the end of IL-6 administration. Significant increases in acute-phase proteins (CRP [C reactive protein], fibrinogen) and ESR (Erthrocyte sedimentation rate) were observed in all patients. Stimulatory effects on thrombocytopoiesis were observed at every dose level, and were maximal at 5 micrograms/kg and 10 microgram/kg. There was no tumour response observed during IL-6 administration. Pharmacokinetic profiles performed in 3 patients are consistent with previous reports in adults. IL-6 is a promising new cytokine for paediatric oncology, in particular to increase thrombocyte counts. We recommend that further studies in children proceed at a dose of 5-10 micrograms/kg/day in a once or, better, twice daily administration.