Graphs as aids to knowledge construction: Signaling techniques for guiding the process of graph comprehension.

Graphical displays are frequently used to express quantitative information in texts, but viewers are sometimes unable to comprehend and learn the relevant information. According to a cognitive analysis, graph interpretation involves (a) relatively simple pattern perception and association processes in which viewers can associate graphic patterns to quantitative referents and (b) more complex and error-prone inferential processes in which viewers must mentally transform data. Experiment 1 establishes that graphs can be redesigned to improve viewers' interpretations by minimizing the inferential processes and maximizing the pattern association processes required to interpret relevant information. In Experiments 2 and 3, the researchers isolated one important factor that affects viewers' interpretation (i.e., the perceptual organization of the information in graphs). If relevant quantitative information is perceptually grouped to form visual chunks (because relevant data points are either connected in line graphs or close together in bar graphs), then viewers describe relevant trends. If relevant information is not perceptually grouped, viewers are less likely to comprehend relevant trends. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Feedback induced instabilities in external cavity injection lasers

The authors show that the coherence collapse instability induced by an external cavity is the origin of the previously reported chaos for laser diodes with delayed feedback. This demonstration opens the question as to whether the observed behaviour is an example of optical chaos or rather is a noise driven instability. Methods are suggested by which the issue can be ultimately decided.<>     

An experimental and theoretical analysis of jitter in self-pulsating lasers synchronized to periodic electrical signals

We investigate both experimentally and theoretically the behavior of pulse jitter in compact disk (CD) self-pulsating lasers that have been synchronized to an applied periodic electrical signal. Our investigations reveal that pulse-to-pulse jitter in a synchronized laser is almost entirely unchanged from that in an unsynchronized laser under the same bias conditions. The major effect of synchronization is the suppression of long term jitter.     

Optical lateral inhibition networks that use self-linearized self-electro-optic-effect devices: theory and experiment

The self-linearized self-electro-optic-effect-device (SL-SEED) phenomenon observed with a quantum-well modulator and photodiode serial combination is one of the few practical routes to optical subtraction. A family of optical lateral inhibition architectures based on the SL-SEED that incorporate optical feedback is introduced and their operation confirmed in simulation. A successful experimental demonstration based on these ideas, performing edge-contrast enhancement by lateral inhibition, is described. System interconnections are both optical and electrical, with nonlocal interconnections being made optically by the use of diffractive elements.     

Identification of Apolipoprotein AI as a serum biomarker of chronic kidney disease in liver transplant recipients, using proteomic techniques

Chronic kidney disease (CKD) is a common complication post‐orthotopic liver transplantation (OLT). Development of CKD is detected by monitoring serum urea and creatinine, however disease can occasionally be at an advanced stage before they become abnormal. Therefore, more accurate parameters are required. In order to identify novel biomarkers of CKD, serum was obtained from 47 OLT recipients with CKD (glomerular filtration rate <60 mL/min) and 23 with normal renal function (glomerular filtration rate >90 mL/min). Using the proteomic technique SELDI‐TOF‐MS, three protein biomarkers (55.6 kDa, 9.5 kDa and 11.4 kDa) were identified that, together, could stratify patients into cases or controls with a sensitivity and specificity of 93.6 and 91.3%, respectively. The area under the curve was 0.94. The primary splitter of the groups at 55.6 kDa was an alternative version of a molecule at 27.8 kDa, which was subsequently identified by 1‐D SDS‐PAGE and LC‐ESI‐MS/MS to be Apolipoprotein AI. Protein expression was shown to be reduced in CKD, by both ELISA (p = 0.057) and Western blot analysis (p = 0.003). Apolipoprotein AI is a novel, accurate marker of CKD post‐OLT. It does require further validation in a large, more diverse patient population but could potentially improve detection of CKD.     

Design and construction of an optoelectronic crossbar switchcontaining a terabit per second free-space optical interconnect

The completed detailed design and initial phases of construction of an optoelectronic crossbar demonstrator are presented. The experimental system uses hybrid very large scale integrated optoelectronics technology whereby InGaAs-based detectors and modulators are flip-chip bonded onto silicon integrated circuits. The system aims to demonstrate a 1-Tb/s aggregate data input/output to a single chip by means of free-space optics     

Types of visual–spatial representations and mathematical problem solving.

Although visual-spatial representations are used extensively in mathematics and spatial ability is highly correlated with success in mathematics education, research to date has not demonstrated a clear relationship between use of visual-spatial representations and success in mathematical problem solving. The authors distinguished 2 types of visual-spatial representations: schematic representations that encode the spatial relations described in a problem and pictorial representations that encode the visual appearance of the objects described in the problem. Participants solved mathematical problems and reported on their solution strategies. The authors were able to reliably classify their visual-spatial representations as primarily schematic or primarily pictorial. Use of schematic spatial representations was associated with success in mathematical problem solving, whereas use of pictorial representations was negatively correlated with success. Use of schematic representations was also significantly correlated with one measure of spatial ability. The research therefore helps clarify the relationship between visual imagery, spatial ability, and mathematical problem solving. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

T lymphocyte subsets and activation status in patients following liver transplantation

Changes in T-lymphocyte subsets have previously been shown to relate to clinical events following liver transplantation and be of prognostic significance following renal transplantation. The aim of this study was to examine T lymphocyte subsets, their activation status and the mean fluorescence intensity of cell surface markers by flow cytometric analysis, in peripheral blood of patients following liver transplantation. Stable transplant patients (n=11) had a significantly higher level of activation (HLA-DR expression ) of all T cell subsets: CD3, CD4 and CD8 compared to healthy controls: 17.5% +/- 14.0 (mean +/- SD) vs 4.7 +/- 1.8 (p=0.04), 13.7% +/- 10.3 vs 4.3 +/- 1.7 (p=0.03) and 23.8% +/- 19.9 vs 3.6 +/- 2.4 (p=0.02) respectively. A further increase in activation status occurred in all T cell subsets in association with acute cellular rejection, reaching significance for the CD4+ population: 13.7% +/- 10.2 vs 23.3% +/- 20.6 (p=0.04). The mean fluorescence intensity of the CD3+DR- and CD3+ DR+ populations were increased to 1397 +/- 869 and 1282 +/- 810 following liver transplantation compared to values of 425 +/- 204 and 376 +/- 166 respectively for controls (p<0.05). T-lymphocytes maintain a high level of activation following liver transplantation and continue to express high levels of the surface marker CD3, which may account for the occurrence of acute cellular rejection despite immunosuppression in these patients.     

热插拔电路的TVS钳位

本文探讨了在线卡输入端使用TVS二极管钳位的理由。作者利用典型系统的实验测量得出的瞬态电压波形为基础研究提供了关键参数,并介绍了选择系统保护元件的主要步骤。热插拔电路保护下一代高性能刀片服务器、数据中心、存储和通信基础设施系统使用的电源系统让人们感觉到一种需求——对速度的需求!具体来说,不断提高的处理器时钟速率和数据吞吐量的长期趋势显而易见。