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1.
The multiple view geometry of static scenes is now well understood. Recently attention was turned to dynamic scenes where scene points may move while the cameras move. The triangulation of linear trajectories is now well handled. The case of quadratic trajectories also received some attention. We present a complete generalization and address the problem of general trajectory triangulation of moving points from non-synchronized cameras. Two cases are considered: (i) the motion is captured in the images by tracking the moving point itself, (ii) the tangents of the motion only are extracted from the images. The first case is based on a new representation (to computer vision) of curves (trajectories) where a curve is represented by a family of hypersurfaces in the projective space ?5. The second case is handled by considering the dual curve of the curve generated by the trajectory. In both cases these representations of curves allow: (i) the triangulation of the trajectory of a moving point from non-synchronized sequences, (ii) the recovery of more standard representation of the whole trajectory, (iii) the computations of the set of positions of the moving point at each time instant an image was made. Furthermore, theoretical considerations lead to a general theorem stipulating how many independent constraints a camera provides on the motion of the point. This number of constraint is a function of the camera motion. On the computation front, in both cases the triangulation leads to equations where the unknowns appear linearly. Therefore the problem reduces to estimate a high-dimensional parameter in presence of heteroscedastic noise. Several method are tested.  相似文献   
2.
Mitomycin C and hyperthermia are both toxic to chronically hypoxic EMT6 tumor cells. Combinations of this drug and heat were tested in vitro in normally aerated and chronically hypoxic EMT6 mouse mammary tumor cells to establish whether greater than additive cytotoxicity could be achieved by combined treatment. Cell survival was measured at four concentrations of mitomycin C (0.01, 0.1, 1.0, and 10 microM) at 37 degrees or at elevated temperatures (41, 42, and 43 degrees) for durations of 1, 2, 3, and 6 hr. At 42 degrees, exposure to mitomycin C for 3 and 6 hr produced a 2- to 3-fold increase in hypoxic tumor cell kill at all drug concentrations over that expected for strict additivity. A 15-fold enhancement in the kill of hypoxic tumor cells was obtained at 1.0 and 10 microM mitomycin C at 43 degrees for 6 hr of exposure. Under most conditions, additivity was observed for the antibiotic and heat in oxygenated cells, except at 43 degrees with 0.01 and 0.1 microM mitomycin C following 3 and 6 hr of treatment, conditions under which a 5- to 10-fold potentiation of tumor cell kill was obtained. The rate of formation of reactive metabolites from mitomycin C under anaerobic conditions in EMT6 cell-free preparations was measured. A 30 to 50% increase in alkylating activity was observed at elevated temperatures, suggesting that the enhanced cytotoxicity of mitomycin C with heat toward hypoxic cells may, in part, be due to an increase in activation of the drug.  相似文献   
3.
作为传统建筑设计课的补充,这组练习着眼于建筑环境的时间性及与人的互动。要求学生观察现实中司空见惯却又被传统建筑教育所忽视的,少量纪念性建筑之外的大量建筑都是一个动态的过程,而不仅仅是建筑师的作品。  相似文献   
4.
Multiple mechanisms of drug resistance contribute to treatment failure. Although high-dose therapy attempts to overwhelm these defenses pharmacologically, this approach is only successful in a fraction of treated patients. Many drug resistance mechanisms are shared between malignant and normal cells, but the expression of various drug resistance mechanisms associated with hypoxia is largely confined to tumor tissue. Thus, reversal of this mechanism is likely to provide a therapeutic advantage to the host. This study was designed to define the dose-limiting toxicities and maximum tolerated dose of etanidazole when it is given concurrently with high-dose ifosfamide, carboplatin, and etoposide (ICE), with hematopoietic stem cell support. The maximum tolerated doses of high-dose ICE were administered concurrently with dose escalations of etanidazole, a hypoxic cell sensitizer. All agents were given by 96-h continuous i.v. infusion beginning on day -7. Mesna uroprotection was provided. Autologous marrow and cytokine mobilized peripheral blood progenitor cells were reinfused on day 0. Granulocyte colony-stimulating factor was administered following reinfusion until the granulocytes recovered to > 1000/microliter. Fifty-five adults with advanced malignancies were enrolled in cohorts of five to nine patients. Four dose levels of etanidazole between 3 and 5.5 g/m2/day (12, 16, 20, and 22 g/m2 total doses) and two doses of carboplatin (1600 and 1800 mg/m2 total doses) were evaluated. Seven patients died of organ toxicity (13%); two each from veno-occlusive disease of liver and sepsis; and one each from sudden death, renal failure, and refractory thrombocytopenic hemorrhage. Five deaths occurred at the top dose level. One additional patient suffered a witnessed cardiorespiratory arrest from ventricular fibrillation and was resuscitated. Dose-dependent and largely reversible peripheral neuropathy was observed consisting of two syndromes: severe cramping myalgic/neuralgic pain, predominantly in stocking glove distribution, occurring between day -3 and day 0, and a sensory peripheral neuropathy with similar distribution peaking around day +60. The maximal achievable dose of etanidazole (16 g/m2 dose level) resulted in a mean serum level of 38 micrograms/ml (25-55 micrograms/ml). Etanidazole significantly enhanced host toxicity of high-dose ICE. Effective modulatory doses of etanidazole could not be given with acceptable toxicity using this schedule.  相似文献   
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A comparison of thresholds calculated from a steady-state and a dynamic model of a myelinated nerve fiber is discussed. It is found that these models compare favorably for stimulus pulse durations of l00 ?s or longer.  相似文献   
8.
Extractive-free cork from Quercus suber L. was submitted to a solvolysis treatment with methanolic NaOH which yielded 37% (o.d. cork) of suberin. This mixture of compounds was thoroughly characterized by FTIR, 1H- and 13C-NMR, gas chromatography coupled with mass spectrometric (GC-MS) analysis, vapour pressure osmometry (VPO), mass spectrography (MS) and gel permeation chromatography (GPC). After derivatization, the main components of the volatile fraction, representing less than half of the total, were found to be omega-hydroxymonocarboxylates, alpha, omega-dicarboxylates, simple alkanoates and 1-alkanols, all with chain lengths ranging from C16 to C24. A second fraction, with an average molecular weight about three times higher, was detected by VPO, MS and GPC. The presence of this important fraction in cork suberin had not been recognized in earlier studies. Both fractions constitute interesting precursors for the elaboration of new materials.  相似文献   
9.
<正>随着LEED认证标准的普及,最近关于建筑的讨论常常是以可持续性这一议题为中心的,它成了高人一等或是彰显创造性的标志。然而,在这些讨论中,常常缺乏的是对根本变化的关注,缺乏实现可持续性所需要达成的切实目标。温哥华市和千禧水都(千禧水都项目为  相似文献   
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