130 research outputs found

    Exposing Inter-Virtual Machine Networking Traffic to External Applications

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    Virtualization is a powerful and fast growing technology that is widely accepted throughout the computing industry. The Department of Defense has moved its focus to virtualization and looks to take advantage of virtualized hardware, software, and networks. Virtual environments provide many benefits but create both administrative and security challenges. The challenge of monitoring virtual networks is having visibility of inter-virtual machine (VM) traffic that is passed within a single virtual host. This thesis attempts to gain visibility and evaluate performance of inter-VM traffic in a virtual environment. Separate virtual networks are produced using VMWare ESXi and Citrix XenServer platforms. The networks are comprised of three virtual hosts containing a Domain Controller VM, a Dynamic Host Configuration Protocol server VM, two management VMs, and four testing VMs. Configuration of virtual hosts, VMs, and networking components are identical on each network for a consistent comparison. Transmission Control Protocol (TCP) and User Datagram Protocol (UDP) traffic is generated to test each network using custom batch files, Powershell scripts, and Python code. Results show standard virtual networks require additional resources (e.g., local Intrusion Detection System) and more hands-on administration for real-time traffic visibility than a virtual network using a distributed switch. Traffic visibility within a standard network is limited to using a local packet capture program such as pktcap-uw, tcpdump, or windump. However, distributed networks offer advanced options, such as port mirroring and NetFlow, that deliver higher visibility but come at a higher latency for both TCP and UDP inter-VM traffic

    Studies in Dye-Tracing Technologies in Karst Hydrogeology

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    Information on fluorescent dyes used for water tracing and the results of six studies are reported. Optical brightener, direct yellow, fluorescein, rhodamine (WT), and other dyes are described and the procedures employed in their use ·in the field and in equilibration experiments are discussed. Three of the six studies consisted of investigations of the equilibration with passive detectors of three of the dyes. The absorption of optical brightener on fabric detectors was apparently linear with concentration and with immersion time, while detectors became rapidly saturated with direct yellow. Equilibrium of fluorescein on charcoal detectors with an elutriating solution was not achieved. Several data processing tasks were performed, including the creation of a computer file for field data and the writing-of programs to sort the field data and generate plotted maps, and to display the total fluorescence of samples. A fifth study was based. on a series of dye traces into Royal Spring and Russell Cave Spring in the Inner Bluegrass Karst Region. Samples were collected with an automatic water sampler and the resulting flow velocity determinations combined with discharge data provided values at a number of aquifer parameters. The most interesting result was the very small value for depth of flow. A final study was of fracture traces identified on topographic maps and aerial photographs in the Inner Bluegrass Karst Region. It was found that while more such features were visible on the photographs, some were only apparent on maps

    Beyond Academics: A Model for Simultaneously Advancing Campus-Based Supports for Learning Disabilities, STEM Students’ Skills for Self-Regulation, and Mentors’ Knowledge for Co-regulating and Guiding

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    Learning disabilities are highly prevalent on college campuses, yet students with learning disabilities graduate at lower rates than those without disabilities. Academic and psychosocial supports are essential for overcoming challenges and for improving postsecondary educational opportunities for students with learning disabilities. A holistic, multi-level model of campus-based supports was established to facilitate culture and practice changes at the institutional level, while concurrently bolstering mentors’ abilities to provide learning disability-knowledgeable support, and simultaneously creating opportunities for students’ personal and interpersonal development. Mixed methods were used to investigate implementation of coordinated personal, interpersonal, and institutional level supports for undergraduate science, technology, engineering, and math (STEM) students with learning disabilities. A one-group pre-test post-test strategy was used to examine undergraduate outcomes. Participants included 52 STEM undergraduates with learning disabilities, 57 STEM graduate student mentors, 34 STEM faculty mentors, and 34 university administrators and personnel as members of a university-wide council. Enrolled for 2 years, undergraduates were engaged in group meetings involving psychoeducation and reflective discussions, development of self-advocacy projects, and individual mentorship. Undergraduates reported improved self-efficacy (p = 0.001), campus connection (p < 0.001), professional development (p ≤ 0.002), and self-advocacy (p < 0.001) after two academic years. Graduate student mentors increased their understanding about learning disabilities and used their understanding to support both their mentees and other students they worked with. Council members identified and created opportunities for delivering learning disability-related trainings to faculty, mentors and advisors on campus, and for enhancing coordination of student services related to learning and related disorders. Disability-focused activities became integrated in broader campus activities regarding diversity. This research explicates a role that college campuses can play in fostering the wellbeing and the academic and career development of its students with developmental learning and related disorders. It offers an empirically tested campus-based model that is multilevel, holistic, and strengths-based for supporting positive outcomes of young people with learning disabilities in STEM. Moreover, findings advance the knowledge of supports and skills that are important for self-regulating and navigating complex and multi-faceted disability-related challenges within both the postsecondary educational environment and the young adults’ sociocultural context

    Evidence for language transfer leading to a perceptual advantage for non-native listeners

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    Phonological transfer from the native language is a common problem for non-native speakers that has repeatedly been shown to result in perceptual deficits vis-a-vis native speakers. It was hypothesized, however, that transfer could help, rather than hurt, if it resulted in a beneficial bias. Due to differences in pronunciation norms between Korean and English, Koreans in the U.S. were predicted to be better than Americans at perceiving unreleased stops--not only in their native language (Korean) but also in their non-native language (English). In three experiments, Koreans were found to be significantly more accurate than Americans at identifying unreleased stops in Korean, at identifying unreleased stops in English, and at discriminating between the presence and absence of an unreleased stop in English. Taken together, these results suggest that cross-linguistic transfer is capable of boosting speech perception by non-natives beyond native levels

    An Unusual Topological Structure of the HIV-1 Rev Response Element

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    SummaryNuclear export of unspliced and singly spliced viral mRNA is a critical step in the HIV life cycle. The structural basis by which the virus selects its own mRNA among more abundant host cellular RNAs for export has been a mystery for more than 25 years. Here, we describe an unusual topological structure that the virus uses to recognize its own mRNA. The viral Rev response element (RRE) adopts an “A”-like structure in which the two legs constitute two tracks of binding sites for the viral Rev protein and position the two primary known Rev-binding sites ∼55 Å apart, matching the distance between the two RNA-binding motifs in the Rev dimer. Both the legs of the “A” and the separation between them are required for optimal RRE function. This structure accounts for the specificity of Rev for the RRE and thus the specific recognition of the viral RNA

    Randomized elimination and prolongation of ACE inhibitors and ARBs in coronavirus 2019 (REPLACE COVID) Trial Protocol

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    Severe acute respiratory syndrome coronavirus 2 (SARS- CoV- 2), the virus responsible for coronavirus disease 2019 (COVID- 19), is associated with high incidence of multiorgan dysfunction and death. Angiotensin- converting enzyme 2 (ACE2), which facilitates SARS- CoV- 2 host cell entry, may be impacted by angiotensin- converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs), two commonly used antihypertensive classes. In a multicenter, international randomized controlled trial that began enrollment on March 31, 2020, participants are randomized to continuation vs withdrawal of their long- term outpatient ACEI or ARB upon hospitalization with COVID- 19. The primary outcome is a hierarchical global rank score incorporating time to death, duration of mechanical ventilation, duration of renal replacement or vasopressor therapy, and multiorgan dysfunction severity. Approval for the study has been obtained from the Institutional Review Board of each participating institution, and all participants will provide informed consent. A data safety monitoring board has been assembled to provide independent oversight of the project.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/163400/2/jch14011_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/163400/1/jch14011.pd

    Phylogenomics reveals the history of host use in mosquitoes

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    Mosquitoes have profoundly affected human history and continue to threaten human health through the transmission of a diverse array of pathogens. The phylogeny of mosquitoes has remained poorly characterized due to difficulty in taxonomic sampling and limited availability of genomic data beyond the most important vector species. Here, we used phylogenomic analysis of 709 single copy ortholog groups from 256 mosquito species to produce a strongly supported phylogeny that resolves the position of the major disease vector species and the major mosquito lineages. Our analyses support an origin of mosquitoes in the early Triassic (217 MYA [highest posterior density region: 188–250 MYA]), considerably older than previous estimates. Moreover, we utilize an extensive database of host associations for mosquitoes to show that mosquitoes have shifted to feeding upon the blood of mammals numerous times, and that mosquito diversification and host-use patterns within major lineages appear to coincide in earth history both with major continental drift events and with the diversification of vertebrate classes. © 2023, Springer Nature Limited

    A molten salt test loop for component and instrumentation testing

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    Molten salt is an effective coolant for a wide range of applications, including nuclear reactors, concentrated solar power, and other high temperature industrial heat transfer processes. The technical readiness level of components and instrumentation for high-temperature molten salt applications needs improvement for molten salt to be more widely adopted. A molten salt test loop was designed, built, and commissioned as a test bed to address these issues. The molten salt test loop at Abilene Christian University was built out of 316 stainless steel with a forced flow centrifugal-type pump, and was instrumented for remote operation. A low-temperature molten nitrate salt was used in this system, which was designed to operate at temperatures up to 300 ◦C and flow rates up to 90 liters per minute. This paper describes the loop design, computational fluid dynamics modeling, construction, and commissioning details. An outline of the data acquisition and control systems is presented. Salt samples were taken before and after introduction into the loop, and melting points were measured both before and after salt circulation. Performance of the system is discussed as well as improvements required for higher temperature loops envisioned for the future
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