控制之外——丹麦哥本哈根机场航站楼的天然光效果

哥本哈根机场被认为是世界上最好的机场之一。建筑在结构上非同一般：曲面钢构件筑成独特的尖拱，建筑因此而得到很多昵称，比如“鲸鱼”。旅客行进在建筑物内，天然光支配着空间的氛围。随着自然光和天气的变化，从精心设置的窗户和天窗内射入的光线经过空间的反射，也在不断变化着，为空间体验增添了又一层维度。     

Limits to the evolution of dispersal kernels under rapid fragmentation

Adaptive evolution of dispersal strategies is one mechanism by which species can respond to rapid environmental changes. However, under rapid anthropogenic fragmentation, the evolution of dispersal may be limited, and species may be unable to adequately adapt to fragmented landscapes. Here, we develop a spatially explicit model to investigate the evolution of dispersal kernels under various combinations of fragmentation dynamics and initial conditions. We also study the consequences of modelling an evolutionary process in which dispersal phenotypes continuously and gradually shift in phenotype space in a manner corresponding to a polygenic underlying genetic architecture. With rapid fragmentation rates, we observed the emergence of long-term transient states in which dispersal strategies are not well suited to fragmented landscapes. We also show that the extent and length of these transient states depend on the pre-fragmentation dispersal strategy of the species, as well as on the rate of the fragmentation process leading to the fragmented landscape. In an increasingly fragmented world, understanding the ability of populations to adapt, and the effects that rapid fragmentation has on the evolution of dispersal, is critical for an informed assessment of species viability in the Anthropocene.     

Evaluating the Mflops measure

Mflops is a simple, effective performance measure, but results vary greatly with architecture and application. To preserve the measure's usefulness, we need new models that reflect various computer configurations     

In vitro expression of the diphtheria toxin A-chain gene under the control of human chorionic gonadotropin gene promoters as a means of directing toxicity to ovarian cancer cell lines

OBJECTIVE: Our goal was to determine whether toxicity of the diphtheria toxin A-chain gene regulated by the human chorionic gonadotropin promoter can be directed to malignant ovarian cell lines. STUDY DESIGN: Plasmids containing diphtheria toxin A-chain gene linked to the regulatory elements of the metalloergothioneine and human chorionic gonadotropin promoters were transfected into the cell lines. Expression of diphtheria toxin A-chain gene was determined by the inhibition of a cotransfected luciferase reporter gene. RESULTS: Cytotoxicity of the diphtheria toxin A-chain gene is shown in a dose-responsive manner. Transfection of a plasmid expressing the diphtheria toxin A-chain gene controlled by a constitutive promoter readily inhibits protein synthesis. Specific inhibition of luciferase protein synthesis occurs in ovarian cancer cells transfected with the diphtheria toxin A-chain gene under the control of the human chorionic gonadotropin promoters when compared with normal ovarian epithelial cells or fibroblasts. CONCLUSIONS: These data demonstrate the preferential expression of the diphtheria toxin A-chain gene, regulated by the human chorionic gonadotropin promoter, to ovarian cancer cell lines. This provides an avenue for targeting such cells for suicide, toxin, or cytokine genes.     

Cat-scratch disease osteomyelitis from a dog scratch

Osteomyelitis is a rare manifestation of cat-scratch disease in patients who do not have AIDS. The clinical presentation and non-specific subacute course of the disease make diagnosis difficult. We present a child with osteomyelitis of a metacarpal following a dog scratch. Bartonella henselae was found to be the aetiological agent. The bone healed after treatment with antibiotics. Increased awareness and a comprehensive medical history are needed to identify patients with suspected Bartonella henselae osteomyelitis.     

Scalable,hierarchical, Ethernet transport network architecture (HETNA)

Ethernet technology is not inherently scalable, and yet, Ethernet dominates LANs, and recently has diffused to access, aggregation networks, and MANs. Ethernet is even considered for transport networks in the backbone. Many solutions from IEEE, IETF, and MEF are considered for enabling Ethernet beyond LANs and bridged LANs. In this paper we offer HETNA, a hierarchical Ethernet forwarding, which is compatible with legacy networks used by enterprises, carriers, and backbone networks, and provides scalability, mobility, protection, multicasting, and QoS support to intra- and inter-domain networks in an efficient forwarding manner. The suggested architecture can handle streaming, real-time, multicasting, and other applications as well as various addressing mechanisms (e.g., IP or URI addressing). Both connection-oriented transport services and connectionless-oriented services are possible in the suggested architecture. This architecture was simulated and prototyped, showing significant improvements over regular Ethernet in terms of buffers and control messages that enable this network to function.     

Innovative ESD thermoplastic composites structured through meltflow processing

The amount of carbon black required to impart electrical conductivity to an insulating polymer can be dramatically reduced by its selective localization in a multi-component system which includes the insulating polymer The present report describes property-structure relationships of polypropylene/nylon/glass fiber (PP/PA/GF) composites with consistent resistivity levels within the 10⁶-10⁹ ohms/sq range achieved at very low carbon black loadings (less than 2%). The quaternary composites studied structure spontaneously during the hot compounding/processing steps and have unique triple-percolation structures. The results were compared with typical carbon black filled materials, which usually contain 15 to 20 wt% carbon black and are too conductive to meet the 10⁶-10⁹ ohms/sq range     

Microbiological cultures of heart valves and valve tags are not valuable for patients without infective endocarditis who are undergoing valve replacement

We evaluated the significance of the results of microbiological cultures of heart valves and identification tags from newly inserted prosthetic valves that were removed from patients with valvular heart disease; none of these patients had a preoperative diagnosis of endocarditis. We reviewed the charts of patients with positive cultures for evidence of infections before or after surgery. Cultures were positive for 11.9% of 219 valves (206 native valves and 13 prosthetic or bioprosthetic valves) and 11.6% of 224 tags. The most common isolates were coagulase-negative staphylococci. Typical agents of endocarditis--viridans streptococcus, Enterococcus faecalis, and Staphylococcus aureus--were cultured from five specimens, and Mycobacterium avium complex was identified in six valves. None of the patients with positive valve or tag cultures developed postsurgical endocarditis or wound infection. Findings on histopathologic examination of the valves were not consistent with endocarditis. We conclude that the results of cultures of valves from patients without preoperative diagnoses of endocarditis lack clinical significance, and positive tag cultures are not predictive of postsurgical infection. Positive cultures are most likely a result of contamination during surgery or thereafter.