2,004 research outputs found

    Usable Authentication for Mobile Banking

    Get PDF
    Mobile banking is attractive because it allows people to do banking anytime, anywhere. One of the requirements of performing a mobile banking transaction is that users are required to login before use. The current mobile banking login method is PIN authentication; however, results from other research studies have found that there are usability concerns of using PINs. To overcome some of the concerns, researchers have suggested the use graphical passwords. In this research, we argue that another alternative input technique can be utilized. We explore a novel password input approach, called gesture passwords, of using 3-dimensional discrete gesture motions as password elements. As a result, three systems (PINs, graphical passwords and gesture passwords) were compared. This dissertation describes the design of two mobile authentication techniques: combinational graphical passwords and gesture passwords. These systems were implemented as prototypes. The prototypes along with a PIN authenticator were evaluated with users. User experience and password retention were evaluated to determine the usability and users’ acceptance of each system. Experiments were conducted to evaluate the above. Results from the experiments show that users were able to use all of the testing systems; however, the results reveal that users are more proficient and preferred to use PINs for mobile banking authentication than the other two systems

    The ecology of seamounts: structure, function, and human impacts.

    Get PDF
    In this review of seamount ecology, we address a number of key scientific issues concerning the structure and function of benthic communities, human impacts, and seamount management and conservation. We consider whether community composition and diversity differ between seamounts and continental slopes, how important dispersal capabilities are in seamount connectivity, what environmental factors drive species composition and diversity, whether seamounts are centers of enhanced biological productivity, and whether they have unique trophic architecture. We discuss how vulnerable seamount communities are to fishing and mining, and how we can balance exploitation of resources and conservation of habitat. Despite considerable advances in recent years, there remain many questions about seamount ecosystems that need closer integration of molecular, oceanographic, and ecological research

    Security of Mobile Banking

    Get PDF
    Mobile banking is attractive because it is a convenient approach to perform remote banking, but there are security shortfalls in the present mobile banking implementations. This paper discusses some of these security shortfalls, such as security problems with GSM network, SMS/GPRS protocols and security problems with current banks’ mobile banking solutions. This paper discusses the SMS and GPRS proposed solutions for these problems. The results from these proposed solutions have proven to provide secure and economic communications between the mobile application and the bank servers.The proposed solutions allow the users to bank using secure SMS and GPRS

    Protection of cerebral microcirculation, mitochondrial function and electrocortical activity by small-volume resuscitation with terlipressin in a model of haemorrhagic shock

    Get PDF
    Background During early treatment of haemorrhagic shock, cerebral perfusion pressure can be restored by small-volume resuscitation with vasopressors. Whether this therapy is improved with additional fluid remains unknown. We assessed the value of terlipressin and lactated Ringer’s solution (LR) on the early recovery of the microcirculation, tissue oxygenation, and mitochondrial and electrophysiological function in the rat cerebral cortex. Methods Animals treated with LR replacing three times (3x) the volume bled (n=26), terlipressin (n=27), terlipressin plus LR of 1x (n=26), 2x (n=16), or 3x (n=15) were compared with untreated (n=36) and sham-operated rats (n=17). In vivo confocal microscopy was used to assess cortical capillary perfusion, changes in tissue oxygen concentration, and mitochondrial membrane potential and redox state. Electrophysiological function was assessed by cortical somatosensory evoked potentials (SEPs), spinal cord dorsum potential, and peripheral electromyography. Results Compared with sham, the mean (SD) area of perfused vessels was lower in rats subjected to haemorrhagic shock: 82 (10)% vs. 38 (12)%; P<0.001) and impaired oxygen concentration, mitochondrial redox state (99±4 vs. 59±15 % of baseline; P<0.001), and SEPs (97±13% vs. 27±19% of baseline). Adminstration of terlipressin plus 1X or 2X LR was able to recover these measures, but terlipressin+3LR or 3LR alone were not as effective. Spinal cord dorsum potential was preserved in all groups, but no therapy protected electromyographic function. Conclusion Resuscitation from haemorrhagic shock using terlipressin with small-volume LR was superior to high-volume LR, with regard to cerebral microcirculation, and mitochondrial and electrophysiological function

    Hypothermia protects brain mitochondrial function from hypoxemia in a murine model of sepsis

    Get PDF
    Sepsis is commonly associated with brain dysfunction, but the underlying mechanisms remain unclear, although mitochondrial dysfunction and microvascular abnormalities have been implicated. We therefore assessed whether cerebral mitochondrial dysfunction during systemic endotoxemia in mice increased mitochondrial sensitivity to a further bioenergetic insult (hyoxemia), and whether hypothermia could improve outcome. Mice (C57bl/6) were injected intraperitoneally with lipopolysaccharide (LPS) (5 mg/kg; n = 85) or saline (0.01 ml/g; n = 47). Six, 24 and 48h later, we used confocal imaging in vivo to assess cerebral mitochondrial redox potential and cortical oxygenation in response to changes in inspired oxygen. The fraction of inspired oxygen (FiO2) at which the cortical redox potential changed was compared between groups. In a subset of animals, spontaneous hypothermia was maintained or controlled hypothermia induced during imaging. Decreasing FiO2 resulted in a more reduced cerebral redox state around veins but preserved oxidation around arteries. This pattern appeared at a higher FiO2 in LPS-injected animals, suggesting an increased sensitivity of cortical mitochondria to hypoxemia. This increased sensitivity was accompanied by a decrease in cortical oxygenation, but was attenuated by hypothermia. These results suggest that systemic endotoxemia influences cortical oxygenation and mitochondrial function, and that therapeutic hypothermia can be protective

    Control over phase separation and nucleation using a laser-tweezing potential

    Get PDF
    Control over the nucleation of new phases is highly desirable but elusive. Even though there is a long history of crystallization engineering by varying physicochemical parameters, controlling which polymorph crystallizes or whether a molecule crystallizes or forms an amorphous precipitate is still a poorly understood practice. Although there are now numerous examples of control using laser-induced nucleation, the absence of physical understanding is preventing progress. Here we show that the proximity of a liquid–liquid critical point or the corresponding binodal line can be used by a laser-tweezing potential to induce concentration gradients. A simple theoretical model shows that the stored electromagnetic energy of the laser beam produces a free-energy potential that forces phase separation or triggers the nucleation of a new phase. Experiments in a liquid mixture using a low-power laser diode confirm the effect. Phase separation and nucleation using a laser-tweezing potential explains the physics behind non-photochemical laser-induced nucleation and suggests new ways of manipulating matter

    Exoanal ultrasound of the anal sphincter: normal anatomy and sphincter defects

    Full text link
    To describe the sonographic appearance of normal anal sphincter anatomy and sphincter defects evaluated with a conventional 5 MHz convex transducer placed on the perineum. Design Prospective, single-blind study. Setting Department of Obstetrics and Gynecology, University of Michigan Medical Center, USA. Population Twenty-five women with symptoms of faecal incontinence, 11 asymptomatic nulliparous women, and 32 asymptomatic parous women. Methods A convex scanner was placed on the perineum with the woman in lithotomy position. Images were taken at three levels of the sphincter canal. Pictures were evaluated by two examiners who were blinded to the case history of the women and to the results of each other for the presence or absence of sphincter defects. Main outcome measures Description of anal sphincter appearance on endoanal ultrasound. Reproducibilty of the evaluation of sphincter defects. Results The internal anal sphincter is visible as a hypoechoic circle; the external anal sphincter shows a hyperechoic pattern. Proximally the sling of the puborectalis muscle is visible. Sphincter defects were detected in 20 women. In all five women who subsequently underwent surgery, the presence and location of the defect was confirmed at the time of surgery. Examiners were in agreement 100% of the time on the presence or absence of internal defects. They disagreed in one patient on the presence of an external defect. Conclusion Exoanal ultrasound provides information on normal anatomy and on defects of the anal sphincter.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75125/1/j.1471-0528.1997.tb12056.x.pd

    Nonabelian Faddeev-Niemi Decomposition of the SU(3) Yang-Mills Theory

    Full text link
    Faddeev and Niemi (FN) have introduced an abelian gauge theory which simulates dynamical abelianization in Yang-Mills theory (YM). It contains both YM instantons and Wu-Yang monopoles and appears to be able to describe the confining phase. Motivated by the meson degeneracy problem in dynamical abelianization models, in this note we present a generalization of the FN theory. We first generalize the Cho connection to dynamical symmetry breaking pattern SU(N+1) -> U(N), and subsequently try to complete the Faddeev-Niemi decomposition by keeping the missing degrees of freedom. While it is not possible to write an on-shell complete FN decomposition, in the case of SU(3) theory of physical interest we find an off-shell complete decomposition for SU(3) -> U(2) which amounts to partial gauge fixing, generalizing naturally the result found by Faddeev and Niemi for the abelian scenario SU(N+1) -> U(1)^N. We discuss general topological aspects of these breakings, demonstrating for example that the FN knot solitons never exist when the unbroken gauge symmetry is nonabelian, and recovering the usual no-go theorems for colored dyons.Comment: Latex 30 page

    Synergy between loss of NF1 and overexpression of MYCN in neuroblastoma is mediated by the GAP-related domain

    Get PDF
    Earlier reports showed that hyperplasia of sympathoadrenal cell precursors during embryogenesis in Nf1-deficient mice is independent of Nf1’s role in down-modulating RAS-MAPK signaling. We demonstrate in zebrafish that nf1 loss leads to aberrant activation of RAS signaling in MYCN-induced neuroblastomas that arise in these precursors, and that the GTPase-activating protein (GAP)-related domain (GRD) is sufficient to suppress the acceleration of neuroblastoma in nf1-deficient fish, but not the hypertrophy of sympathoadrenal cells in nf1 mutant embryos. Thus, even though neuroblastoma is a classical “developmental tumor”, NF1 relies on a very different mechanism to suppress malignant transformation than it does to modulate normal neural crest cell growth. We also show marked synergy in tumor cell killing between MEK inhibitors (trametinib) and retinoids (isotretinoin) in primary nf1a-/- zebrafish neuroblastomas. Thus, our model system has considerable translational potential for investigating new strategies to improve the treatment of very high-risk neuroblastomas with aberrant RAS-MAPK activation

    The cometary composition of a protoplanetary disk as revealed by complex cyanides

    Full text link
    Observations of comets and asteroids show that the Solar Nebula that spawned our planetary system was rich in water and organic molecules. Bombardment brought these organics to the young Earth's surface, seeding its early chemistry. Unlike asteroids, comets preserve a nearly pristine record of the Solar Nebula composition. The presence of cyanides in comets, including 0.01% of methyl cyanide (CH3CN) with respect to water, is of special interest because of the importance of C-N bonds for abiotic amino acid synthesis. Comet-like compositions of simple and complex volatiles are found in protostars, and can be readily explained by a combination of gas-phase chemistry to form e.g. HCN and an active ice-phase chemistry on grain surfaces that advances complexity[3]. Simple volatiles, including water and HCN, have been detected previously in Solar Nebula analogues - protoplanetary disks around young stars - indicating that they survive disk formation or are reformed in situ. It has been hitherto unclear whether the same holds for more complex organic molecules outside of the Solar Nebula, since recent observations show a dramatic change in the chemistry at the boundary between nascent envelopes and young disks due to accretion shocks[8]. Here we report the detection of CH3CN (and HCN and HC3N) in the protoplanetary disk around the young star MWC 480. We find abundance ratios of these N-bearing organics in the gas-phase similar to comets, which suggests an even higher relative abundance of complex cyanides in the disk ice. This implies that complex organics accompany simpler volatiles in protoplanetary disks, and that the rich organic chemistry of the Solar Nebula was not unique.Comment: Definitive version of the manuscript is published in Nature, 520, 7546, 198, 2015. This is the author's versio
    corecore