695 research outputs found
Will mobile video become the killer application for 3G? - an empirical model for media convergence
Mobile carriers have continually rolled out 3G mobile video applications to increase their revenue and profits. The presumption is that video is superior to the already successful SMS, ringtones, and pictures, and can create greater value to users. However, recent market surveys revealed contradicting results. Motivated by this discrepancy, we propose in this paper a parsimonious model for user acceptance of mobile entertainment as digital convergence. Integrating research on Information Systems, Flow, and Media Psychology, we take a unique approach to user acceptance of digital convergence - platform migration. Our key proposition is that the interaction between media types and the platform-specific constraints is the key determinant of user evaluation. Particularly, users' involvement in the media is determined by both the entertaining time span on the original platform and the attentional constraint of the new platform. The mismatch between the two spans can result in lower level involvement, which in turn cause no or even negative user emotional responses. The model was tested with empirical data. We discuss the theoretical contributions, strategic and design implications, and future research directions derived from this theoretical framewor
Evolution Of Feeding Shapes Swimming Kinematics Of Barnacle Naupliar Larvae: A Comparison Between Trophic Modes
A central goal in evolutionary biology is connecting morphological features with ecological functions. For marine invertebrate larvae, appendage movement determines locomotion, feeding, and predator avoidance ability. Barnacle larvae are morphologically diverse, and the morphology of non-feeding lecithotrophic nauplii are distinct from those that are planktotrophic. Lecithotrophic larvae have a more globular body shape and simplified appendages when compared with planktotrophs. However, little is known about whether and how such morphological changes affect kinematics, hydrodynamics, and ecological functions. Here, we compared the nauplii kinematics and hydrodynamics of a lecithotrophic Rhizocephalan species, Polyascus planus, against that of the planktotrophic nauplii of an intertidal barnacle, Tetraclita japonica. High-speed, micro-particle image velocimetry analysis showed that the Polyascus nauplii swam faster and had higher amplitude and more synchronous appendage beating than the Tetraclita nauplii. This fast swimming was accompanied by a faster attenuation of induced flow with distance, suggesting reduced predation risk. Tetraclita nauplii had more efficient per beat cycles with less backward displacement during the recovery stroke. This âanchoring effectâ resulted from the anti-phase beating of appendages. This movement, together with a high-drag body form, likely helps direct the suction flow toward the ventral food capturing area. In sum, the tradeoff between swimming speed and predation risks may have been an important factor in the evolution of the observed larval forms
A Tailâs Tale: Biomechanical Roles Of Dorsal Thoracic Spine Of Barnacle Nauplii
Many marine invertebrates have complex life histories that begin with a planktonic larval stage. Similar to other plankton, these larval invertebrates often possess protruding body extensions, but their function beyond predator deterrence is not well-documented. For example, the planktonic nauplii of crustaceans have spines. Using the epibiotic pedunculate barnacle Octolasmis spp., we investigated how the dorsal thoracic spine affects swimming and fluid disturbance by comparing nauplii with their spines partially removed against those with intact spines. Our motion analysis showed that amputated Octolasmis spp. swam slower, in jerkier trajectories, and were less efficient per stroke cycle than those with intact spines. Amputees showed alterations in limb beat pattern: larger beat amplitude, increased phase lag, and reduced contralateral symmetry. These changes might partially help increase propulsive force generation and streamline the flow, but were insufficient to restore full function. Particle image velocimetry further showed that amputees had a larger relative area of influence, implying elevated risk by rheotactic predator. Body extensions and their interactions with limb motion play important biomechanical roles in shaping larval performance, which likely influences the evolution of form
Preserving Both Privacy and Utility in Network Trace Anonymization
As network security monitoring grows more sophisticated, there is an
increasing need for outsourcing such tasks to third-party analysts. However,
organizations are usually reluctant to share their network traces due to
privacy concerns over sensitive information, e.g., network and system
configuration, which may potentially be exploited for attacks. In cases where
data owners are convinced to share their network traces, the data are typically
subjected to certain anonymization techniques, e.g., CryptoPAn, which replaces
real IP addresses with prefix-preserving pseudonyms. However, most such
techniques either are vulnerable to adversaries with prior knowledge about some
network flows in the traces, or require heavy data sanitization or
perturbation, both of which may result in a significant loss of data utility.
In this paper, we aim to preserve both privacy and utility through shifting the
trade-off from between privacy and utility to between privacy and computational
cost. The key idea is for the analysts to generate and analyze multiple
anonymized views of the original network traces; those views are designed to be
sufficiently indistinguishable even to adversaries armed with prior knowledge,
which preserves the privacy, whereas one of the views will yield true analysis
results privately retrieved by the data owner, which preserves the utility. We
present the general approach and instantiate it based on CryptoPAn. We formally
analyze the privacy of our solution and experimentally evaluate it using real
network traces provided by a major ISP. The results show that our approach can
significantly reduce the level of information leakage (e.g., less than 1\% of
the information leaked by CryptoPAn) with comparable utility
Gene-by-Intervention Effects on Alcohol Dependence Symptoms in Emerging Adulthood
The Importance of Peer Influence for LGBTQ+ Youth in Rural Communities
Aaron Kemmerer
supported by findings from Safe as Yourself (SAY) Project
Traci Wike (PI), Leah Bouchard, Maurico Yabar, and Aaron Kemmerer
Objectives: To explore the experiences and narratives of LGBTQ+ youth in rural North Carolina. To elaborate on the influence of peer support and impact of peer victimization for LGBTQ+ youth in rural North Carolina.
Methods: Data was collected from eleven young people who were interviewed from 2019-2020 at an LGBTQ+ youth center in rural North Carolina. The interviews were coded and analyzed using narrative analysis on a team of interraters; the team consisted of four members from VCU School of Social Work: the principle investigator, two doctoral research assistants, and an MSW research assistant.
Results: Analysis of the interviews, though still in process, so far highlights the impact of the dual impact of participantsâ peers --- simultaneously pointing to LGBTQ+ youth experiences with both peer victimization (as a risk factor) and peer support (as a resilience factor).
Conclusions: Peer support is vital for LGBTQ+ youth in rural communities and may help offset the negative impact of peer victimization.https://scholarscompass.vcu.edu/gradposters/1059/thumbnail.jp
ICT application in teaching and learning
The purpose of this study was to investigate and assess the use of ICT in the teaching-learning process. This study assessed the senior high school students of PAU Excellencia Global Academy Foundation, Inc.âs studentsâ attitudes toward ICT integration and the effectiveness of ICT use in the teaching-learning process. The effectiveness of using ICT in the teaching-learning process, as well as the level of attitude toward ICT among the secondary school students participating in the research, were evaluated by the researcher using a descriptive-correlational engaging quantitative approach. As to the findings , one of the most important contributing aspects affecting a studentâs success in various subjects and fields is their performance. Generous investments were justified by the firmly held belief that technology may improve student academic achievement by enabling more effective and efficient ICT integration into teaching-learning process for students
Burrow Architecture of the Ghost Crab Ocypode ceratophthalma on a Sandy Shore in Hong Kong
One-carbon metabolism in cancer
Cells require one-carbon units for nucleotide synthesis, methylation and reductive metabolism, and these pathways support the high proliferative rate of cancer cells. As such, anti-folates, drugs that target one-carbon metabolism, have long been used in the treatment of cancer. Amino acids, such as serine are a major one-carbon source, and cancer cells are particularly susceptible to deprivation of one-carbon units by serine restriction or inhibition of de novo serine synthesis. Recent work has also begun to decipher the specific pathways and sub-cellular compartments that are important for one-carbon metabolism in cancer cells. In this review we summarise the historical understanding of one-carbon metabolism in cancer, describe the recent findings regarding the generation and usage of one-carbon units and explore possible future therapeutics that could exploit the dependency of cancer cells on one-carbon metabolism
An Unexpected Location of the Arginine Catabolic Mobile Element (ACME) in a USA300-Related MRSA Strain
In methicillin resistant Staphylococcus aureus (MRSA), the arginine catabolic mobile element (ACME) was initially described in USA300 (t008-ST8) where it is located downstream of the staphylococcal cassette chromosome mec (SCCmec). A common health-care associated MRSA in Copenhagen, Denmark (t024-ST8) is clonally related to USA300 and is frequently PCR positive for the ACME specific arcA-gene. This study is the first to describe an ACME element upstream of the SCCmec in MRSA. By traditional SCCmec typing schemes, the SCCmec of t024-ST8 strain M1 carries SCCmec IVa, but full sequencing of the cassette revealed that the entire J3 region had no homology to published SCCmec IVa. Within the J3 region of M1 was a 1705 bp sequence only similar to a sequence in S. haemolyticus strain JCSC1435 and 2941 bps with no homology found in GenBank. In addition to the usual direct repeats (DR) at each extremity of SCCmec, M1 had two new DR between the orfX gene and the J3 region of the SCCmec. The region between the orfX DR (DR1) and DR2 contained the ccrAB4 genes. An ACME II-like element was located between DR2 and DR3. The entire 26,468 bp sequence between DR1 and DR3 was highly similar to parts of the ACME composite island of S. epidermidis strain ATCC12228. Sequencing of an ACME negative t024-ST8 strain (M299) showed that DR1 and the sequence between DR1 and DR3 was missing. The finding of a mobile ACME II-like element inserted downstream of orfX and upstream of SCCmec indicates a novel recombination between staphylococcal species
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