Whole-stream metabolism: strategies for measuring and modeling diel trends of dissolved oxygen

Stream metabolism is used to characterize the allochthonous and autochthonous basis of stream foodweb production. The metabolic rates of respiration and gross primary production often are estimated from changes in dissolved O2 concentration in the stream over time. An upstream–downstream O2 accounting method (2-station) is used commonly to estimate metabolic rates in a defined length of stream channel. Various approaches to measuring and analyzing diel O2 trends have been used, but a detailed comparison of different approaches (e.g., required reach length, method of measuring aeration rate [k], and use of temperature-corrected metabolic rates) is needed. We measured O2 upstream and downstream of various reaches in Kings Creek, Kansas. We found that 20 m was the approximate minimum reach length required to detect a significant change in O2, a result that matched the prediction of a calculation method to determine minimum reach length. We assessed the ability of models based on 2-station diel O2 data and k measurements in various streams around Manhattan, Kansas, to predict k accurately, and we tested the importance of accounting for temperature effects on metabolic rates. We measured gas exchange directly with an inert gas and used a tracer dye to account for dilution and to measure velocity and discharge. Modeled k was significantly correlated with measured k (Kendall's τ, p < 0.001; regression adjusted R²  =  0.70), but 19 published equations for estimating k generally provided poor estimates of measured k (only 6 of 19 equations were significantly correlated). Temperature correction of metabolic rates allowed us to account for increases in nighttime O2, and temperature-corrected metabolic rates fit the data somewhat better than uncorrected estimates. Use of temperature-correction estimates could facilitate cross-site comparisons of metabolism

Securing Wearables through the Creation of a Personal Fog

Increased reliance on wearables using Bluetooth requires additional security and privacy measures to protect these devices and personal data, regardless of device vendor. Most wearables lack the ability to monitor their communication connections and protect personal data without assistance. Attackers can force wearables to disconnect from base stations. When a wearable loses its connection to its base station, an attacker can connect to the wearable to steal stored personal data or await reconnection to the base station to eavesdrop on communications. If the base station inadvertently disconnects from the cloud serving a security-aware app, it would be unable to respond to a rapid change in the security of its current environment. We design a personal fog incorporating wearables, a base station, and the cloud that allows the wearable to be situationally aware and manage inter- and intra-fog communications, given local personal fogs with the same app

Absorption of nutrients by aquatic plants

Formulae are derived for the rate of nutrient absorption by aquatic plants approximating the shapes of spheres, discs, cylinders, and plates. Other parameters are the size and specific gravity of the plant, the nutrient concentration of the medium, and the physical properties affecting the transfer of nutrients toward the plant surface. The formulae allow for convection, i. e., the movement of water relative to the plant. Hence absorption is aided by a current in the case of attached plants and by a rapid sinking rate in the case of plankton. The results are not materially modified by turbulence...

Providing Deaf People with the Opportunity for a Degree: Benefits to Individual and Society

This study was conducted to determine the extent to which individual and societal financial sacrifices necessary to support postsecondary education for deaf people are worthwhile by determining the relationship of college to both higher salaries for deaf individuals and additional taxes paid to the government. The Internal Revenue Service provided data on earnings of, and taxes paid by, several groups of college applicants: those not accepted; no- shows; withdrawals; sub-bachelor graduates; and bachelor degree recipients. Projections of their earnings received and taxes paid over 20 years were made. Principal findings were that, after20 years: (1) deaf Bachelor degree recipients will have earned roughly $220,000 more than sub-Bachelor alumni and$320,000-$365,000 more than persons without degrees; and (2)deaf Bachelor graduates will have paid approximately$89,000morein taxes than those with sub-Bachelor degrees and $126,000-$140,000 more than those without degrees. Both individual and society benefit economically when deaf people earn postsecondary degrees

Toward Predicting Secure Environments for Wearable Devices

Wearable devices have become more common for the average consumer. As devices need to operate with low power, many devices use simplified security measures to secure the data during transmission. While Bluetooth, the primary method of communication, includes certain security measures as part of the format, they are insufficient to fully secure the connection and the data transmitted. Users must be made aware of the potential security threats to the information communicated by the wearable, as well as be empowered and engaged to protect it. In this paper, we propose a method of identifying insecure environments through crowdsourced data, allowing wearable consumers to deploy an application on their base system (e.g., a smart phone) that alerts when in the presence of a security threat. We examine two different machine learning methods for classifying the environment and interacting with the users, as well as evaluating the potential uses for both algorithms

Some phases of mutual insurance in the United States

Thesis (BL)--University of Illinois, 1894TypescriptIncludes bibliographical references ( leaf [12]

Social interactions in two groups of zoo-housed adult female Asian elephants (Elephas maximus) that differ in relatedness

Opportunities for positive social interaction are important in captive animals, and social interactions can be used as a welfare indicator. Wild elephants live in related multigenerational herds; however, in captivity they are often managed in less related groups, which could impact the quality of their social interactions, and thus their welfare. Here, we used a limited social network analysis to investigate the social interactions in two groups of four female captive Asian elephants, one of which contained individuals that were all related to one another, whilst the other was a mix of related and unrelated individuals. Data on pairwise social interactions was collected from eight days of video footage using an all-occurrence sampling technique. More affiliative, and fewer agonistic interactions were observed in the related elephant group. Additionally, non-contact displacement was observed at a higher frequency in the related elephant group, which we theorise represents an established functioning hierarchy, avoiding the need for overt aggression over resources. Although kinship is not likely to be the only factor affecting captive elephant social behaviour, these findings support the recommendation that for optimal welfare, elephants should be managed in multigenerational family herds. Evaluations of social interactions such as those conducted here would have wider applicability for aiding the management of any captive social species to identify when groups might be incompatible

Determinants of Childhood Adiposity: Evidence from the Australian LOOK Study

BACKGROUND To contribute to the current debate as to the relative influences of dietary intake and physical activity on the development of adiposity in community-based children. METHODS Participants were 734 boys and girls measured at age 8, 10 and 12 years for percent body fat (dual emission x-ray absorptiometry), physical activity (pedometers, accelerometers); and dietary intake (1 and 2-day records), with assessments of pubertal development and socioeconomic status. RESULTS Cross-sectional relationships revealed that boys and girls with higher percent body fat were less physically active, both in terms of steps per day and moderate and vigorous physical activity (both sexes p<0.001 for both measures). However, fatter children did not consume more energy, fat, carbohydrate or sugar; boys with higher percent body fat actually consumed less carbohydrate (p = 0.01) and energy (p = 0.05). Longitudinal analysis (combined data from both sexes) was weaker, but supported the cross-sectional findings, showing that children who reduced their PA over the four years increased their percent body fat (p = 0.04). Relationships in the 8 year-olds and also in the leanest quartile of all children, where adiposity-related underreporting was unlikely, were consistent with those of the whole group, indicating that underreporting did not influence our findings. CONCLUSIONS These data provide support for the premise that physical activity is the main source of variation in the percent body fat of healthy community-based Australian children. General community strategies involving dietary intake and physical activity to combat childhood obesity may benefit by making physical activity the foremost focus of attention.The financial support provided by the Commonwealth Education Trust (London, UK) was vital to the completion of this work, and the authors thank the Board of Trustees for supporting them over several years. The authors also thank members of The Canberra Hospital Salaried Staff Specialists Private Practice Fund for their financial contribution to the study. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

Pilots, Airspace Complexity, and Strategic Conflict Avoidance

Some future air traffic management concepts seek to place more separation responsibility on the pilot in order to achieve greater aircraft operating autonomy. Separating one’s own aircraft from others in something other than a see-and-avoid environment, however, would pose fundamentally new demands and challenges for pilots, and it is likely that new automation and display tools would be needed. Ideally, an automated strategic conflict avoidance system would behave consistently with pilot expectations and take pilot interests into account when suggesting resolution strategies. It might also recognize situations that pilots may have difficulty detecting and resolving on their own. At this time, little is known about how pilots perceive airspace complexity in self-separation tasks. In this study, we used a Cockpit Display of Traffic Information (CDTI) with an embedded strategic conflict avoidance aid to help fourteen commercial transport pilots detect and resolve a series of strategic conflict situations. We then assessed their performance with and without the aid, recorded and analyzed pilot ratings of aid effectiveness and usability, and used a neural network model to associate complexity ratings with airspace characteristics to determine which sets of characteristics most heavily influenced pilot perceptions of airspace complexity. The results of this analysis provide insight into what aspects of airspace configuration may have the greatest influence on pilot perceived workload and difficulty understanding conflict situations