Integrated band demultiplexer using waveguide grating routers

We present a novel band demultiplexer design for planar lightwave circuits. It consists of two perfectly sampled waveguide grating routers connected by sets of equal-path-length waveguides separated on one side. Its advantages are compactness, sharp passband corners, and a lack of chromatic dispersion.     

天然纤维在产业和动态负荷结构中的应用

1990年初以来,天然纤维增强复合材料在静态和中等受力状态下的应用,例如帽子支架、汽车车顶和汽车内部衬里,是众所周知的。正如这些例子所表明的,天然纤维增强复合材料具有多种用途,但最近二三年里发展不快。介绍了天然纤维纺织半成品的特定组合用于承受动态负荷的踏板车横梁的可能性．以及这种材料组合中所用的纺织品类型和能达到的机械性能。     

Single longitudinal-mode stability via wave mixing in long-cavitysemiconductor lasers

We show that with the appropriate intracavity filter, wave mixing due to carrier depletion guarantees stable single longitudinal mode operation in long-cavity semiconductor lasers, We experimentally demonstrate the principle using a multifrequency waveguide grating router laser     

Radioimmunoassay of oestrone in plasma. A comparison of different methods with respect to the relation between assay specificity, sample purification and antibody specificity

A radioimmunoassay (RIA) for oestrone (Oe1) in plasma was developed using an ether extraction, a partition between NaOH and light petroleum, and a TLC as sample purification and an antiserum cross-reacting with Oe2 for the final assay (Method A1). The reliability criteria are given in detail. In order to simplify this method a highly specific antiserum was developed by using Oe1-3-hemisuccinate-BSA as an antigen. Using this antiserum for the final assay but omitting the TLC (Method B) the Oe1 concentration in male plasma was 76% overestimated (Method B compared with Method A1). In pregnancy plasma Oe1 could specifically be determined after a simple ether extraction (Method C). It was concluded that the use of a highly specific antiserum (as determined by cross-reaction studies) for the final assay does not necessarily imply that a chromatographic sample purification can be omitted without loss in assay specificity. This appears to be true mainly in cases where the steroid concentration of the sample is low. Normal values of Oe1 from 80 healthy adult males were ascertained by Method A1. Age group I (22-61 years, n = 48) ranged from 1.22-5.60 ng/100 ml, median 2.81; age group II (67-90 years, n = 32) from 1.55-6.40, 100 median 3.41. The small increase of Oe1 with age was highly significant.     

Preoperative fasting improves survival after 90% hepatectomy

OBJECTIVE: To assess whether alterations in preoperative fatty acid oxidation and gluconeogenesis induced by fasting will affect survival and liver regeneration following 90% hepatectomy in the rat. DESIGN: In a randomized, controlled trial, Wistar rats (N = 157) were separated into two groups. Rats in the first group fasted for 24 hours. Rats in the second group were allowed to eat ad libitum until the time of operation. These groups were further randomized to receive either 20% glucose or tap water ad libitum postoperatively. INTERVENTIONS: Ninety percent hepatectomy; 24-hour fast; 5% glucose feeding. MAIN OUTCOME MEASURES: Survival, DNA synthesis in the hepatic remnant along with glucokinase activity (GKA) and glycogen content, serum ketone bodies (KB), free fatty acid (FFA), glucose, and ad libitum glucose consumption (GC) were serially quantified. RESULTS: Fasting rats that were offered glucose (fasted/glucose) after hepatectomy demonstrated better survival at 48 hours than the rats that were fed before the procedure and given glucose following hepatectomy (fed/glucose), 95% vs 52% (P < .05). The fasted/glucose group also had a greater peak rate of DNA synthesis (550 +/- 110 vs 275 +/- 40 disintegrations per minute per 0.001 mg of DNA, P < .05). Survival was poor in both groups when only tap water was offered to the animals after hepatectomy (31% vs 12%). In the fasted/glucose group, GC 1 hour after hepatectomy was greater than that for fed rats (1.3 +/- 0.175 vs 0.73 +/- 0.176 g/h, P < .05), yet GKA was suppressed (3.4 +/- 0.42 vs 8.05 +/- 2.77 nmol/min per milligrams of protein, P < .05). Fasting before hepatectomy and consuming glucose after causes elevations in both FFA (1.26 +/- 0.19 vs 0.82 +/- 0.13 mol/mL., P < .05) and KB (18.96 +/- 2.82 vs 11.4 +/- 3.94 mmol/mL, P < .05). Normal glucose was maintained in the fasted/glucose group, but fell to 63 +/- 14 mg/dL at 8 hours after hepatectomy in the fed/glucose group. CONCLUSIONS: Fasting before hepatectomy shifts energy utilization to fat oxidation and gluconeogenesis, which appears to ameliorate liver failure after hepatectomy in this severe model of hepatic resection.     

Factors associated with dental anxiety

This study assessed dental anxiety in adults living in the Detroit tricounty area and identified factors associated with it. The prevalence of dental anxiety was 10.0 percent. Regression analysis revealed six factors associated with dental anxiety: unfavorable attitudes toward dentists, infrequent checkups, dissatisfaction with one's month, small numbers of filled surfaces, being female and lower income. Dentists should be aware of these factors when assessing dental anxiety in their patient populations.     

All-Optical Network Consortium-ultrafast TDM networks

We describe recent results of the Advanced Research Projects Agency (ARPA) sponsored Consortium on Wideband All-Optical Networks which is developing architectures, technology components, and applications for ultrafast 100 Gb/s time-division multiplexing (TDM) optical networks. The shared-media ultrafast networks we envision are appropriate for providing low-access-delay bandwidth on demand to both future high-burst rate (100 Gb/s) users as well aggregates of lower-rate users (i.e., a heterogeneous user population). To realize these goals we are developing ultrafast network architectures such as HLAN, described here, that operate well in high-latency environments and require only limited processing capability at the ultrafast bit rates. We also describe results on 80-Gb/s, 90-km soliton transmission, 100-Gb/s soliton compression laser source technology, picosecond short-pulse fiber ring lasers, picosecond-accuracy optical bit-phase sensing and clock recovery, all-optical injection-locked fiber figure-eight laser clock recovery, short-pulse fiber loop storage, and all-optical pulse width and wavelength conversion     

Quasi-random rumor spreading: Reducing randomness can be costly

We give a time-randomness tradeoff for the quasi-random rumor spreading protocol proposed by Doerr, Friedrich and Sauerwald [SODA 2008] on complete graphs. In this protocol, the goal is to spread a piece of information originating from one vertex throughout the network. Each vertex is assumed to have a (cyclic) list of its neighbors. Once a vertex is informed by one of its neighbors, it chooses a position in its list uniformly at random and then informs its neighbors starting from that position and proceeding in order of the list. Angelopoulos, Doerr, Huber and Panagiotou [Electron. J. Combin. 2009] showed that after rounds, the rumor will have been broadcasted to all nodes with probability 1−o(1).We study the broadcast time when the amount of randomness available at each node is reduced in natural way. In particular, we prove that if each node can only make its initial random selection from every ?-th node on its list, then there exists lists such that steps are needed to inform every vertex with probability at least . This shows that a further reduction of the amount of randomness used in a simple quasi-random protocol comes at a loss of efficiency.     

CRM<Emphasis Type="SmallCaps">ba</Emphasis> a CRM extension for the documentation of standing buildings

Exploring the connections between successive phases and overlapping layers from different ages in an ancient building is paramount for its understanding and study. Archaeologists and cultural heritage experts are always eager to unveil the hidden relations of an archaeological building to reconstruct its history and for its interpretation. This paper presents CRMba, a CIDOC CRM extension developed to facilitate the discovery and the interpretation of archaeological resources through the definition of new concepts required to describe the complexity of historic buildings. The CRMba contributes to solving the datasets interoperability issue by exploiting the use of the CIDOC CRM to overcome data fragmentation, to investigate the semantics of building components, of functional spaces and of the construction phases of historic buildings and complexes, making explicit their physical and topological relations through time and space. The approach used for the development of the CRMba makes the model valid for the documentation of different kinds of buildings, across periods, styles and conservation state.     

Issues in an inference platform for generating deductive knowledge: a case study in cultural heritage digital libraries using the CIDOC CRM

Most information retrieval research focuses collecting documents that match the same set of concepts. This study considers a more advanced problem, namely how to discover knowledge not contained in a single source from combined historical facts. By using a well-designed core ontology in the cultural domain (CIDOC CRM, ISO21127), this study discusses the requirement for a robust inference platform for real-life knowledge discovery and integration over distributed sources. The methodology and design are justified in detail through functional requirements for an inference service with the capability of inferring new knowledge from combinations of facts distributed over different sources. A number of critical issues for developing such a robust inference platform are identified, namely (1) systematic accumulation of common concepts and inference rules; (2) extending the ontology with metaclasses; (3) accumulation of factual and categorical knowledge; (4) incorporation of fuzzy inference into the inference engine, and (5) improvement of performance and scalability in the inference engine.