Use of simple thermodynamic and structural parameters to predict self-reactivity hazard ratings of chemicals

A major problem in the transportation, transfer and storage of bulk chemicals is the problem of catastrophic instability under unforeseen situations. N     

COLONIAL PLACE,NORFOLK: RESIDENTIAL INTEGRATION IN A SOUTHERN URBAN NEIGHBORHOOD

Racial integration on a neighborhood scale is a relatively new phenomenon in southern cities. The experience of the Colonial Place neighborhood in Norfolk, Virginia, since the middle 1960s provides evidence for testing generalizations about the factors required for stable racial integration. The paper suggests that the characteristics of racial relations in the South may allow socioeconomic heterogeneity to be compatible with racial integration. It also suggests that the increasing availability of procedures and programs for community planning and community conservation provide effective tools which neighborhood organizations can adapt to the goal of racial integration.     

Viscoelastic study of ionomers

Stress-relaxation curves were obtained for ionomers containing different cations, per cents of ionization, and thermal treatments. Differences in the rheological behavior were found to depend more on the ionization level than on the ion. A recently proposed model for ionomers is discussed and found to be consistent with these results. In terms of this model the degree of ionization in the polymer acts as a regulator for the growth of small oriented lamellar (crystalline) regions. In the most general terms, the mechanical behavior and strength of ionomers appears dominated by the existence of “hard” regions interspersed among “soft” regions. In the polymers studied here there was some slight crystallinity; however, similar effects and explanations are probably suitable for amorphous “ionomers.” Toughness was also found in some completely amorphous carboxylcontaining copolymers without added ionic salts. The same explanation of “hard” regions interspersed among soft regions is also valid here. The “blocky” nature of the copolymerization may play a role in setting up this type of structure.     

Dialysis Disequilibrium Syndrome Revisited

An aggressive dialysis in a grossly azotemic patient, especially one with severe metabolic acidosis, can lead to dialysis disequilibrium syndrome (DDS). Mild forms present as nausea, vomiting, restlessness, and headache. Severe manifestations include seizures, obtundation, coma, and even death. This clinical picture is caused by cerebral edema induced by one or more of the following mechanisms:

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Sequestration of Host Plant Glucosinolates in the Defensive Hemolymph of the Sawfly Athalia rosae

Interactions between insects and glucosinolate-containing plant species have been investigated for a long time. Although the glucosinolate–myrosinase system is believed to act as a defense mechanism against generalist herbivores and fungi, several specialist insects use these secondary metabolites for host plant finding and acceptance and can handle them physiologically. However, sequestration of glucosinolates in specialist herbivores has been less well studied. Larvae of the turnip sawfly Athalia rosae feed on several glucosinolate-containing plant species. When larvae are disturbed by antagonists, they release one or more small droplets of hemolymph from their integument. This reflex bleeding is used as a defense mechanism. Specific glucosinolate analysis, by conversion to desulfoglucosinolates and analysis of these by high-performance liquid chromatography coupled to diode array UV spectroscopy and mass spectrometry, revealed that larvae incorporate and concentrate the plant's characteristic glucosinolates from their hosts. Extracts of larvae that were reared on Sinapis alba contained sinalbin, even when the larvae were first starved for 22 hr and, thus, had empty guts. Hemolymph was analyzed from larvae that were reared on either S. alba, Brassica nigra, or Barbarea stricta. Leaves were analyzed from the same plants the larvae had fed on. Sinalbin (from S. alba), sinigrin (B. nigra), or glucobarbarin and glucobrassicin (B. stricta) were present in leaves in concentrations less than 1 mol/g fresh weight, while the same glucosinolates could be detected in the larvae's hemolymph in concentrations between 10 and 31 mol/g fresh weight, except that glucobrassicin was present only as a trace. In larval feces, only trace amounts of glucosinolates (sinalbin and sinigrin) could be detected. The glucosinolates were likewise found in freshly emerged adults, showing that the sequestered phytochemicals were transferred through the pupal stage.     

First impressions: A multicultural content analysis of professional psychology program Web sites.

With the ascension of the Internet as an information resource, Web sites are likely to be the first exposure applicants have to specific programs. The authors evaluated professional psychology program Web sites for ethnic and sexual orientation minority content, discovering that diversity content of Web sites was considerably less than in previously examined paper application materials. Clinical psychology programs were more likely to state a commitment to diversity training while counseling psychology programs were more likely to state a diversity minor/track. School psychology programs had the lowest diversity content on their Web pages. This article explores how graduate psychology program Web sites communicate multicultural information and offers recommendations on using the World Wide Web as a cost-effective tool to attract a diverse student body. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Efficiently Scaling up Crowdsourced Video Annotation

We present an extensive three year study on economically annotating video with crowdsourced marketplaces. Our public framework has annotated thousands of real world videos, including massive data sets unprecedented for their size, complexity, and cost. To accomplish this, we designed a state-of-the-art video annotation user interface and demonstrate that, despite common intuition, many contemporary interfaces are sub-optimal. We present several user studies that evaluate different aspects of our system and demonstrate that minimizing the cognitive load of the user is crucial when designing an annotation platform. We then deploy this interface on Amazon Mechanical Turk and discover expert and talented workers who are capable of annotating difficult videos with dense and closely cropped labels. We argue that video annotation requires specialized skill; most workers are poor annotators, mandating robust quality control protocols. We show that traditional crowdsourced micro-tasks are not suitable for video annotation and instead demonstrate that deploying time-consuming macro-tasks on MTurk is effective. Finally, we show that by extracting pixel-based features from manually labeled key frames, we are able to leverage more sophisticated interpolation strategies to maximize performance given a fixed budget. We validate the power of our framework on difficult, real-world data sets and we demonstrate an inherent trade-off between the mix of human and cloud computing used vs. the accuracy and cost of the labeling. We further introduce a novel, cost-based evaluation criteria that compares vision algorithms by the budget required to achieve an acceptable performance. We hope our findings will spur innovation in the creation of massive labeled video data sets and enable novel data-driven computer vision applications.     

Control and Navigation Framework for Quadrotor Helicopters

This paper presents the development of a nonlinear quadrotor simulation framework together with a nonlinear controller. The quadrotor stabilization and navigation problems are tackled using a nested loops control architecture. A nonlinear Backstepping controller is implemented for the inner stabilization loop. It asymptotically tracks reference attitude, altitude and heading trajectories. The outer loop controller generates the reference trajectories for the inner loop controller to reach the desired waypoint. To ensure boundedness of the reference trajectories, a PD controller with a saturation function is used for the outer loop. Due to the complexity involved in controller development and testing, a simulation framework has been developed. It is based on the Gazebo 3D robotics simulator and the Open Dynamics Engine (ODE) library. The framework can effectively facilitate the development and validation of controllers. It has been released and is available at Gazebo quadrotor simulator (2012).