A8高速路公园

Koog aan de Zaan是阿姆斯特丹附近的个可爱的小村庄，坐落于Zaan河边。20世纪70年代早期，这里新建了条高速路。为了跨过河，A8高速下面由桥墩支撑。这条新路奇妙地穿过镇子，在城市肌理中形成了个粗暴的切口。具有讽刺意义的是，在这里形成了个教会和政府间的根本分离：高架路的一侧是一个小教堂，而另一侧则是原来的市政厅。桥墩大概有7米高。桥下的空间变得非常具有纪念性：成为一个延伸的教堂。     

Correcting C-band radar reflectivity and differential reflectivitydata for rain attenuation: a self-consistent method withconstraints

Quantitative use of C-band radar measurements of reflectivity (Z _h) and differential reflectivity (Z_dr) demands the use of accurate attenuation-correction procedures, especially in convective rain events. With the availability of differential phase measurements (Φ_dp) with a dual-polarized radar, it is now possible to improve and stabilize attenuation-correction schemes over earlier schemes which did not use Φ_dp. The recent introduction of constraint-based correction schemes using Φ_dp constitute an important advance. In this paper, a self-consistent, constraint-based algorithm is proposed and evaluated which extends the previous approaches in several important respects. Radar data collected by the C-POL radar during the South China Sea Monsoon Experiment (SCSMEX) are used to illustrate the correction scheme. The corrected radar data are then compared against disdrometer-based scattering simulations, the disdrometer data being acquired during SCSMEX. A new algorithm is used to retrieve the median volume diameter from the corrected Z_h, corrected Z_dr , and K_dp radar measurements which is relatively immune to the precise drop axis ratio versus drop diameter relation. Histograms of the radar-retrieved D₀ compared against D₀ from disdrometer data are in remarkable good agreement lending further validity to the proposed attenuation-correction scheme, as well as to confidence in the use of C-band radar for the remote measurement of rain microphysics     

Neonatal murine B lymphocytes respond to polysaccharide antigens in the presence of IL-1 and IL-6

Unlike adults, neonates are unable to respond to polysaccharide Ags, making them especially vulnerable to pathogenic encapsulated bacteria. Since the Ab response to polysaccharides in adult mice requires certain cytokines, it was hypothesized that neonatal murine B cells may be competent to respond to such Ags, but may fail to do so due to a deficiency of cytokines. Neonatal splenocyte cultures, which were otherwise unresponsive to trinitrophenyl (TNP)-Ficoll, a haptenated polysaccharide Ag, mounted an adult-like Ab response when supplemented with IL-1. However, IL-1 failed to induce such a response to TNP-Ficoll when purified B cells were used instead. Although IL-6 alone did not induce a response in whole spleen cells or purified B cells from neonates, it synergized with IL-1 in inducing purified neonatal B cells to respond to TNP-Ficoll. The avidity of the cytokine-induced neonatal anti-TNP Abs was comparable to that of Abs made by adult splenocyte cultures. One effect of IL-1 may be at the level of clonal expansion, since it induced neonatal B cells to proliferate in response to anti-IgM, which was further enhanced by IL-6. The spontaneous secretion of IL-1 by neonatal splenocytes was below the detection limit, while adult splenocytes secreted 30.8 +/- 5.2 U/ml, which is of the same order of magnitude as what was required to stimulate neonatal B cells to respond to TNP-Ficoll. Thus, the neonatal unresponsiveness to polysaccharide Ags could be due to the inability of a non-B cell population resident in the neonatal spleen to secrete sufficient quantities of IL-1.     

Prevention of neonatal group B streptococcal infection

Neonatal group B streptococcal infection is the primary cause of neonatal morbidity related to infection. It can often be prevented by identifying and treating pregnant women who carry group B streptococci or who are at highest risk of transmitting the bacteria to newborns. Increasing evidence and expert opinion support intrapartum treatment of women at relatively high risk of delivering an infant with group B streptococcal infection. Such women can be identified through the use of an anogenital culture for group B streptococci obtained at 35 to 37 weeks of gestation and by the presence of at least one of many risk factors associated with neonatal infection. These risk factors include preterm labor or rupture of the membranes at less than 37 weeks of gestation, previous delivery of an infant with invasive group B streptococcal disease, group B streptococcal bacteriuria during the present pregnancy, maternal intrapartum fever of 38 degrees C (100.4 degrees F) or higher and rupture of the fetal membranes for 18 hours or more. The recommended agent for intrapartum chemoprophylaxis is intravenous penicillin G; clindamycin is used in penicillin-allergic women. The use of risk markers alone to guide the administration of intrapartum antibiotics is much more cost-effective than other preventive strategies, but it exposes more women and infants to antibiotic-associated risks. Management of the infants of treated mothers is empiric and is currently guided by expert opinion.     

An epidemic of roller-blade injuries in children

Roller blading is a new and increasingly popular leisure activity in many countries. We reviewed 110 consecutive patients with roller-blade injuries between 1 January and 30 June 1996. The patients ranged from 4 to 14 years in age (mean 6.5 years). Eighty-three (75.4%) sustained injuries to the upper limb and 27 (24.5%) injured the lower limb. Fifty-six patients, were girls and 54 were boys. Of the 110 patients, 79 (72.7%) sustained fractures, 28 (25.4%) soft tissue injuries and 3 (2.7%) dislocations. Eighty-three (75.4%) of the patients wore no protective equipment on the limbs. Four months following injury 103 (93.6%) patients were fully recovered. The mean duration of school absence was 3 days. Subsequently 101 children returned to using roller-blades following injury. Seventy-three (66.3%) of these now use protective equipment. We found that injuries were unrelated to age or duration of roller-blading experience or to the brand-name of roller blades used, and that most of our patients wore no protective equipment at the time of injury.     

Composition and synthesis of three higher ganglioside homologs in bovine mammary tissue

Three higher gangliosides were identified as constituents of bovine mammary gland. The structures of these three gangliosides were shown to be ceramide-glucose-galactose-(sialic acid)-N-acetylgalactosamine-galactose, ceramide-glucose-galactose-(sialic acid)₂-N-acetylgalactosamine, and ceramide-glucose-galactose-(sialic acid)₂-N-acetylgalactosamine-galactose These gangliosides accounted for only a small fraction (<20%) of the lipid-bound sialic acid in mammary gland. While fatty acids with even carbon numbers from C₁₄ to C₂₆ were predominant in these gangliosides, they also contained C₂₃ and C₂₅ fatty acids. Mammary gland Golgi apparatus-rich fractions had all glycosyltransferases required for synthesis of these gangliosides starting with ceramide.