Benthic video image analysis facilitates monitoring of Dreissena populations across spatial scales

In contrast to marine systems where remote sensing methods in studies of benthic organisms have been widely used for decades, these methods have experienced limited use in studies of freshwater benthos due to the general lack of large epifauna. The situation has changed with the introduction of dreissenid bivalves capable of creating visible aggregations on lake bottoms into North American freshwaters in the 1980s and 1990s. The need for assessment of Dreissena densities prompted exploration of videography as a potentially cost-effective tool. We developed a novel sampling method that analyzes video recorded using a GoPro camera mounted to a benthic sled to estimate Dreissena coverage, density, and biomass over relatively large areas of the lake bed in the Laurentian Great Lakes compared to traditional sampling methods. Using this method, we compared quagga mussel coverage, density, and biomass estimates based on three replicate Ponar grabs vs. 500?m-long video transects across 43 stations sampled in Lake Michigan in 2015. Our results showed that analysis of images from video transects dramatically increased the bottom area surveyed compared to Ponar grabs and increased the precision of Dreissena density and biomass estimations at monitoring stations. By substantially increasing the ability to detect relatively small (<20%) changes between years within a particular station, this method could be a useful and cost-effective addition for monitoring Dreissena populations in the Great Lakes and other freshwater systems where they occur.     

Physiological response to firefighting activities of various work cycles using extended duration and prototype SCBA

Firefighters’ self-contained breathing apparatus (SCBA) protects the respiratory system during firefighting but increases the physiological burden. Extended duration SCBA (>30 min) have increased air supply, potentially increasing the duration of firefighting work cycles. To examine the effects of SCBA configuration and work cycle (length and rest), 30 firefighters completed seven trials using different SCBA and one or two bouts of simulated firefighting following work cycles common in the United States. Heart rate, core temperature, oxygen consumption, work output and self-reported perceptions were recorded during all activities. Varying SCBA resulted in few differences in these parameters. However, during a second bout, work output significantly declined while heart rates and core temperatures were elevated relative to a single bout. Thirty seven per cent of the subjects were unable to complete the second bout in at least one of the two-bout conditions. These firefighters had lower fitness and higher body mass than those who completed all assigned tasks.

Practitioner Summary: The effects of extended duration SCBA and work/rest cycles on physiological parameters and work output have not been examined. Cylinder size had minimal effects, but extended work cycles with no rest resulted in increased physiological strain and decreased work output. This effect was more pronounced in firefighters with lower fitness.     

Maintaining censorship resistance in the iTrust network for publication,search and retrieval

This paper presents the architecture of the iTrust system together with algorithms for maintaining censorship resistance. In iTrust, metadata describing documents, and requests containing keywords, are distributed to randomly chosen nodes in the iTrust network. If a node receives a request containing keywords that match metadata it holds, it sends the URL of the matching document to the requesting node, which then retrieves the document from the source node. A novel detection algorithm estimates the proportion of operational nodes in the iTrust network, by comparing the empirical probabilities of the number of responses received for a node’s request with the analytical probabilities for a match, for various proportions of operational nodes. A novel defensive adaptation algorithm increases the number of nodes to which the requests are distributed, in order to maintain the same high probability of a match when some of the nodes are non-operational or malicious as when all of the nodes are operational. Extensive experimental evaluations demonstrate the effectiveness of the architecture and the algorithms for maintaining censorship resistance in the iTrust network.     

Lithium chloride and avoidance of novel places.

In Exp I, 40 male hooded rats were exposed to a distinctive chamber (Chamber A, part of a 2-chamber apparatus) that was novel for half of the Ss but familiar for the other half. Each S was subsequently injected with lithium chloride or saline. In a test trial conducted 24 hrs later, all Ss were given a choice between Chamber A and Chamber B, which was novel for all Ss. The group made familiar with Chamber A and then given lithium showed a significant preference for that side or an avoidance of the novel side, a "spatial neophobia." Exp II, with 40 Ss, confirmed the spatial neophobia effect and demonstrated that it did not depend on the particular conditioning procedure used in the 1st experiment. The spatial neophobia effect was related to similar effects in the taste aversion literature and to the results of research on lithium-induced decreases in exploratory behavior. (30 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Quantification of sphingolipids in soybeans

Soybean is believed to be a rich source of sphingolipids, a class of polar lipids with desirable biological activities. Analytical methods for sphingolipids vary, and quantitative data for sphingolipids in foods, including soybeans, are scarce. the objectives of this study were to establish a method for quantification of sphingolipids in soybeans and to determine whether genotype, stage of maturity, and growing location affect sphingolipid content in soybeans. Separation of neutral lipids and interfering polar lipids from sphingolipids by saponification, transesterification, and solvent partition was studied. Solvent partition accompanied by TLC purification was determined to be the most accurate sample preparation method for HPLC quantification of cerebroside. There were significant differences in cerebroside concentration among genotypes, with a range of 142 to 492 nmol/g seed (dry wt basis). The differences in cerebroside concentration between immature and mature seeds of one genotype and between two seed production locations of one genotype were considerable but not statistically significant.     

Dense Mullite from Attrition-Milled Kyanite and Aluminum Metal

Dense mullite was produced through the reaction and sintering of an attrition-milled mixture of kyanite (Al₂O₃·SiO₂) and aluminum metal. Kyanite and aluminum were attrition-milled then slowly heated at 1°3C/min to 1100°3C in air, and rapidly heated to 1600°3C and held for 1 h. During heating, the aluminum metal is oxidized first in the solid state and then as a liquid. The attrition-milled kyanite decomposes yielding mullite and rejecting silica, which then reacts with the alumina formed from oxidation of the aluminum. Expansion from the aluminum oxidation and kyanite decomposition partially compensates for the normal sintering shrinkage. A dense, fine-grain-size mullite results.     

Transesterification of brazilian vegetable oils with methanol over ion-exchange resins

The transesterification of several Brazilian vegetable oils with methanol was carried out at 60°C in the presence of several ion-exchange resins having different structures. The vegetable oils used were from Babassu coconut, corn, palm, palm kernel, and soybean. The effect of the methanol/oil mole ratio and the influences of the structure of the ion-exchange resin and the type of vegetable oil used on the catalytic activity of the ionexchange resins were investigated. The resins used were Amberlyst 15, Amberlyst 31, Amberlyst 35, and Amberlyst 36. Amberlyst 15 produced the best results for the transesterification of vegetable oils. The methyl ester yield is higher for palm kernel oil and Babassu coconut oil than for soybean oil, probably owing to their higher content of shorter-chain FA. Therefore, it was shown that the catalytic activity of the resin depends on the FA composition of the vegetable oil employed.     

Model-based diagnosis techniques for Internet delay diagnosis with dynamic routing

In this paper we propose a model-based approach to diagnose latencies in computer networks. We formalize this problem as a model-based diagnosis (MBD) problem and propose a range of methods to solve it. Three solution approaches are proposed: a conflict-directed approach, a constraint satisfaction approach and a linear programming approach. We discuss the pros and cons of these approaches and describe which approaches are suited to handle which network routing policies. In particular we handle this work networks with static routing policies, where there exists a static route between every pair of end-users, as well as two common types of dynamic routing policies, where information between a pair of end users may pass via more than a single route. The performance of the proposed approaches is demonstrated experimentally on two domains: the standard NS2 network simulator and on parts of the Internet topology obtained from the Route Views project. Both able to find diagnoses fast for network models with 1,000 nodes.     

Psychophysiological responses in experienced firefighters undertaking repeated self-contained breathing apparatus tasks

In order to safely and effectively extinguish fires and rescue life, firefighters are required to routinely wear self-contained breathing apparatus (SCBA), yet little is known about the specific physiological and psychological demands associated with repeated exposure to tasks that require SCBA. A total of 12 experienced firefighters took part in a series of commonly encountered SCBA activities: free search, guideline search and live firefighting tasks under room temperature (～20°C) and extreme heat (～180°C) conditions to assess changes in heart rate, blood pressure, mood, perceived workload and air usage. Findings demonstrate that live firefighting is associated with greater perceived exhaustion than free search or guideline exercises; however, all tasks lead to high cardiovascular demand regardless of the presence of heat. No significant impact of task upon mood and no significant differences between the perceived demands of guideline, free search and live firefighting exercises were found.

Practitioner Summary: This study considered the physiological and psychological responses of firefighters undertaking SCBA exercises. Although live firefighting is associated with greater perceived exertion, the absence of differences in psychological domains between exercises demonstrates that task demands are not always dependent upon the presence of fire and that all tasks are mentally challenging.