Self-shading of upwelling irradiance for an instrument with sensors on a sidearm

The self-shading measurement error of the upwelling irradiance that is due to the presence of the instrument housing of an optical spectrometer with the irradiance meter located on a sidearm was calculated with a Monte Carlo code. The dependence of the effect on the instrument dimensions, the values of real optical parameters, sea-surface roughness, and Sun zenith angle were all studied to estimate maximum errors for two possible configurations of a proposed new marine spectrophotometer.     

自反现代主义:21世纪初建筑学的视角立场

区域的跨国性是全球化进程中一项最为重要的产物.地方文化失去了其自明性,不再被当作无可置疑的世界秩序.它不再是一种“自然的”现象,而变成了一种任务,一种思想和行动的目标.我们把这种保持距离的行为看作是对传统的自反.传统的内容和之前含蓄的文化背景体系变得外露并正经历着公众的讨论.就这样,它们摆脱了无期的地狱成为历史的洪流.这使它们的地位发生了根本的改变：从现在起,它们本身不再有效,但需要切实的支持,并用论证来加以证明.它们是可塑造、可改变的;它们将自己定位在一个现实的社会进程中,而不是局限在一个永恒不变的秩序里,也得不到宇宙论及本体论结构的支持.它们失去了社会保障.“我们对世界和自我认识经验的不断调和并没有终结传统,而仅仅是把它反映出来.”然而当前我们所指的全球化本质上仅是马克思和恩格斯在19世纪中叶所描述的社会进程的加速版：连续的产业革命,不断的社会动乱,永恒的不确定和亢奋使资产阶级时代与早于它的所有时代区别开来.所有的固定的、顽固不化的、被确定的社会关系连同它所附带的陈旧的、腐朽的偏见及思想都被打扫干净,所有刚刚诞生的带有偏见和腐朽思想的社会关系都被扼杀在摇篮里.     

Volumetric three-dimensional display systems: their past, presentand future

Volumetric three-dimensional displays are those in which images are generated within a display volume, rather than upon a stationary surface. Since the images are physically three-dimensional, most visual depth cues are automatically satisfied, without the need for observers to wear special glasses or headgear. Moreover, an all-round view of the images is usually possible. Many ideas for volumetric displays have been proposed over the past 60 years or so, and some of these are discussed in this article. Potential applications for such displays are widespread and include fields from scientific and medical research is to engineering design and education     

Mutations of the cystic fibrosis gene in patients with chronic pancreatitis

BACKGROUND: The pancreatic lesions of cystic fibrosis develop in utero and closely resemble those of chronic pancreatitis. Therefore, we hypothesized that mutations of the cystic fibrosis transmembrane conductance regulator (CFTR) gene may be more common than expected among patients with chronic pancreatitis. METHODS: We studied 134 consecutive patients with chronic pancreatitis (alcohol-related disease in 71, hyperparathyroidism in 2, hypertriglyceridemia in 1, and idiopathic disease in 60). We examined DNA for 22 mutations of the CFTR gene that together account for 95 percent of all mutations in patients with cystic fibrosis in the northwest of England. We also determined the length of the noncoding sequence of thymidines in intron 8, since the shorter the sequence, the lower the proportion of normal CFTR messenger RNA. RESULTS: The 94 male and 40 female patients ranged in age from 16 to 86 years. None had a mutation on both copies of the CFTR gene. Eighteen patients (13.4 percent), including 12 without alcoholism, had a CFTR mutation on one chromosome, as compared with a frequency of 5.3 percent among 600 local unrelated partners of persons with a family history of cystic fibrosis (P<0.001). A total of 10.4 percent of the patients had the 5T allele in intron 8 (14 of 134), which is twice the expected frequency (P=0.008). Four patients were heterozygous for both a CFTR mutation and the 5T allele. Patients with a CFTR mutation were younger than those with no mutations (P=0.03). None had the combination of sinopulmonary disease, high sweat electrolyte concentrations, and low nasal potential-difference values that are diagnostic of cystic fibrosis. CONCLUSIONS: Mutations of the CFTR gene and the 5T genotype are associated with chronic pancreatitis.     

Glycosylation reactions in Plasmodium falciparum, Toxoplasma gondii, and Trypanosoma brucei brucei probed by the use of synthetic peptides

D-type cyclins are necessary and rate-limiting for G1 progression during the mammalian cell cycle. Cyclins D1, D2, and D3 are encoded by distinct genes and are expressed in proliferating cells in a lineage-specific manner. Monoclonal antibodies (mAbs) generated to bacterially produced recombinant D-type cyclins were able to react with the native proteins expressed in mammalian cells. One mouse and three rat mAbs immunoprecipitated cyclin D1 from mouse macrophages. Only rat mAbs reacted with human cyclin D1 and cross-reacted with cyclin D2 expressed in proliferating T lymphocytes and human tumor cell lines. A single rat mAb to cyclin D2 exhibited a pattern of reactivity reciprocal to that of rat mAbs to D1. Three rat mAbs reacted specifically with mouse or human cyclin D3, but did not cross-react with cyclins D1 or D2 from either species. Representative mAbs were useful for immunoblotting and detected D-type cyclins coprecipitating in complexes recovered with antiserum to cyclin-dependent kinase-4 (CDK4). Because these mAbs detect D-type cyclins in the nuclei of fixed permeabilized cells, they should prove useful in documenting cyclin overexpression in those human tumors in which the genes are amplified or are targets of specific chromosomal rearrangements.     

Monolithically integrated Gunn oscillator at 35 GHz

A fully planar monolithically integrated Gunn oscillator for 35 GHz has been constructed on a GaAs substrate. An output power of about 1.5 mW, corresponding to an efficiency of 0.5%, is obtained from the oscillator in its present unoptimised form. The device is intended for use as a local oscillator in integrated millimetre-wave receivers. Measurements are made by means of quasi-optical output coupling.     

Memory-enhancing effects of secreted forms of the beta-amyloid precursor protein in normal and amnestic mice

When administered intracerebroventricularly to mice performing various learning tasks involving either short-term or long-term memory, secreted forms of the beta-amyloid precursor protein (APPs751 and APPs695) have potent memory-enhancing effects and block learning deficits induced by scopolamine. The memory-enhancing effects of APPs were observed over a wide range of extremely low doses (0.05-5,000 pg intracerebroventricularly), blocked by anti-APPs antisera, and observed when APPs was administered either after the first training session in a visual discrimination or a lever-press learning task or before the acquisition trial in an object recognition task. APPs had no effect on motor performance or exploratory activity. APPs695 and APPs751 were equally effective in the object recognition task, suggesting that the memory-enhancing effect of APPs does not require the Kunitz protease inhibitor domain. These data suggest an important role for APPss on memory processes.     

An optimal algorithm for the on-line closest-pair problem

We give an algorithm that computes the closest pair in a set ofn points ink-dimensional space on-line, inO(n logn) time. The algorithm only uses algebraic functions and, therefore, is optimal. The algorithm maintains a hierarchical subdivision ofk-space into hyperrectangles, which is stored in a binary tree. Centroids are used to maintain a balanced decomposition of this tree.These authors were supported by the ESPRIT II Basic Research Actions Program, under Contract No. 3075 (project ALCOM).This author was supported in part by the National Science and Engineering Research Council of Canada.