RESTORATION OF SPAWNING HABITATS OF BROWN TROUT (SALMO TRUTTA) IN A REGULATED CHALK STREAM

Gravel bed spawning grounds are essential for the reproduction of salmonids. Such spawning grounds have been severely degraded in many rivers of the world because of river regulation and erosive land use. To reduce its effects on salmonid reproduction rates, river managers have been restoring spawning grounds. However, measures of effectiveness are lacking for the restored spawning sites of brown trout (Salmo trutta). In this study, two methods were used to restore gravel bed spawning grounds in the Moosach River, a chalk stream in Southern Germany: the addition of gravel and the cleaning of colmated gravel. Seven test sites were monitored in the years 2004 to 2008, focussing on sediment conditions. Furthermore, brown trout egg survival and changes in the brown trout population structure were observed. Both gravel addition and gravel cleaning proved to be suitable for creating spawning grounds for brown trout. Brown trout reproduced successfully at all test sites. The relative number of young‐of‐the‐year brown trout increased clearly after the restoration. Sediment on the test sites colmated during the 4 years of the study. In the first 2 years, highly suitable conditions were maintained, with a potential egg survival of more than 50%. Afterwards, the sites offered moderate conditions, indicating an egg survival of less than 50%. Conditions unsuitable for reproduction were expected to be reached 5 to 6 years after restoration. Copyright © 2011 John Wiley & Sons, Ltd.     

Situating Internet Use: Information‐Seeking Among Young Women with Breast Cancer

In recent years considerable attention has been focused on the potential of the Internet as a means of health information delivery that can meet varied health information needs and empower patients. In this article, we explore utilization of the Internet as a means of health information consumption amongst young women with breast cancer who were known Internet users. Focusing on a population known to be competent at using the Internet allowed us to eliminate the digital divide as a possible explanation for limited use of the Internet for health information‐seeking. Ultimately, this allowed us to demonstrate that even in this Internet savvy population, the Internet is not necessarily an unproblematic means of disseminating health care information, and to demonstrate that the huge amount of health care information available does not automatically mean that information is useful to those who seek it, or even particularly easy to find. Results from our qualitative study suggest that young women with breast cancer sought information about their illness in order to make a health related decision, to learn what would come next, or to pursue social support. Our respondents reported that the Internet was one source of many that they consulted when seeking information about their illness, and it was not the most trusted or most utilized source of information this population sought.     

NetGlean: A Methodology for Distributed Network Security Scanning

Network vulnerability analysis tools today do not provide a complete security awareness solution. Currently, network administrators utilize multiple analysis tools in succession or randomly in a patchwork fashion that provides only temporary assurance. This paper introduces NetGlean as a methodology for distributed network security scanning with a holistic approach to network analysis. NetGlean uses new and existing techniques in a continual, autonomous, evolutionary manner to provide powerful real-time and historical views of large and complex networks. This paper introduces the methodology and describes one implementation NetGleanIP, a scanner for IP and converged networks.Gavin W. Manes is a Research Assistant Professor at the Center for Information Security and the University of Tulsa. His research interests are information assurance, digital forensics, telecommunications security, and critical infrastructure protection.Dominic Schulte graduate with his Masters of Computer Science from the University of Tulsa in May 2003. Currently he works as an information security professional.Seth Guenther graduate with his Masters of Computer Science from the University of Tulsa in May 2003. Currently he works as an information security professional.Sujeet Shenoi is the F.P.Walter Professor of Computer Science at the University of Tulsa, Tulsa, Oklahoma. His research interests are in information assurance, digital forensics, critical infrastructure protection, and intelligent control.     

Interactive Broad-Band Dialogue Systems in the Integrated Services Digital Network (ISDN)

In the integrated services digital network of the future, Which will also have broad-band capacity, it will be possible to offer information services with multimedia presentation (e.g., with support of audiovisual material). For easy use, dialogue structures must be developed which lower the barrier of access for casual users. Offering information in a variety of applications at any place, a technical system consisting of different types of storage devices, operating Systems, and terminals, connected by a narrow- and broad-band switching and transmission system, must be available.     

When the Dust Settles: The Four Behaviors of LiDAR in the Presence of Fine Airborne Particulates

This paper describes the behavior of a commercial light detection and ranging (LiDAR) sensor in the presence of dust. This work is motivated by the need to develop perception systems that must operate where dust is present. This paper shows that the behavior of measurements from the sensor is systematic and predictable. LiDAR sensors exhibit four behaviors that are articulated and understood from the perspective of the shape‐of‐return signals from emitted light pulses. We subject the commercial sensor to a series of tests that measure the return pulses and show that they are consistent with theoretical predictions of behavior. Several important conclusions emerge: (i) where LiDAR measures dust, it does so to the leading edge of a dust cloud rather than as a random noise; (ii) dust starts to affect measurements when the atmospheric transmittance is less than 71%–74%, but this is quite variable with conditions; (iii) LiDAR is capable of ranging to a target in dust clouds with transmittance as low as 2% if the target is retroreflective and 6% if it is of low reflectivity; (iv) the effects of airborne particulates such as dust are less evident in the far field. The significance of this paper lies in providing insight into how better to use measurements from off‐the‐shelf LiDAR sensors in solving perception problems.     

Kinetic analysis of thermal degradation of NR/EPDM blends: Effect of the reactive compatibilization

The effect of mercapto‐modified EPDM (EPDMSH) and thioacetate‐modified EPDM (EPDMTA) on the thermal degradation of NR/EPDM (70 : 30 wt %) blends has been investigated under anaerobic and aerobic conditions. The anaerobic condition consisted of compression‐molding the samples at different times, higher than the optimum curing time established by the oscillatory disk rheometer. The aerobic conditions consisted of ageing the samples in an air circulating oven. EPDMTA in the blend resulted in a reasonable retention of mechanical properties of sample ageing in an air‐circulation oven, and a slight increase of crosslink density after ageing under anaerobic conditions. EPDMSH resulted in an accentuated ageing degradation under anaerobic and aerobic conditions. The kinetic parameters of thermal degradation were evaluated from non isothermal TGA experiments taken at different heating rates. The presence of functionalized copolymers in a proportion as low as 2.5 wt % in the blends resulted in a substantial increase of the activation energy, indicating an increase of the resistance against thermal degradation. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 2669–2675, 2007     

Frequency Stability Analysis of Transistorized Crystal Oscillator

This paper gives an analysis of a modified Pierce oscillator for frequency variation due to changes in the circuit or transistor. The magnitudes of the frequency shifts due to parameter changes are computed in relation to each other. The analysis has been verified by testing the oscillator circuit with several transistors which had significantly different measured parameters. Computed frequency shifts were compared with measured frequency shifts. The agreement between experimental and calculated data is ?8×10-9 with a 5 Mc, fifth overtone quartz crystal in the circuit. A general equation relating frequency changes to changes in circuit parameters has been derived and is applicable to any operating frequency as long as the y parameters of the transistor and the circuit elements of the oscillator are known.     

Attaining low percolation threshold in conductive polypropylene/nitrile rubber thermoplastic vulcanizates using carbon nanotube

Electrically conductive thermoplastic vulcanizates (TPV) based on polypropylene (PP)/nitrile rubber (NBR) blends loaded with multiwalled carbon nanotube (CNT) were prepared by dynamic vulcanization. CNT was incorporated into the system using two different mixing sequences: (i) one-step method, by adding CNT after the PP and NBR and (ii) two-steps method involving a previous PP/CNT master batch. Scanning electron microscopy and transmission electron microscopy were used to analyze the morphology of the nanocomposites. Dynamic-mechanical analysis and rheological properties were also used for characterizing the TPV and TPE samples. Both mixing strategies favored the location of the CNT inside the PP phase. The one-step approach resulted in a percolation threshold as low as 0.19 vol% with conductivity value of 0.04 S m⁻¹ for the system loaded with only 0.50 vol% of CNT. The electromagnetic interference shielding effectiveness and microwave absorbing properties were evaluated in the X-band frequency range. The TPV samples prepared by both methods displayed an overall electromagnetic attenuation of around 70%.