Credential hardening by using touchstroke dynamics

Today, reliance on digital devices for daily routines has been shifted towards portable mobile devices. Therefore, the need for security enhancements within this platform is imminent. Numerous research works have been performed on strengthening password authentication by using keystroke dynamics biometrics, which involve computer keyboards and cellular phones as input devices. Nevertheless, experiments performed specifically on touch screen devices are relatively lacking. This paper describes a novel technique to strengthen security authentication systems on touch screen devices via a new sub variant behavioural biometrics called touchstroke dynamics. We capitalize on the high resolution timing latency and the pressure information on touch screen panel as feature data. Following this a light weight algorithm is introduced to calculate the similarity between feature vectors. In addition, a fusion approach is proposed to enhance the overall performance of the system to an equal error rate of 7.71% (short input) and 6.27% (long input)

A Pichia pastoris VPS15 homologue is required in selective peroxisome autophagy

Methylotrophic yeasts contain large peroxisomes during growth on methanol. Upon exposure to excess glucose or ethanol these organelles are selectively degraded by autophagy, Here we describe the cloning of a Pichia pastoris gene (PpVPS15) involved ill peroxisome degradation, which is homologous to Saccharomyces cerevisiae VPS15. In methanol-grown cells of a P. pastoris VPS15 deletion strain, the levels of peroxisomal marker enzymes remained high after addition of excess glucose or ethanol. Electron microscopic studies revealed that the organelles were not taken up by vacuoles, suggesting that PpVPS15 is required at an early stage in peroxisome degradation

Engineering PtRu bimetallic nanoparticles with adjustable alloying degree for methanol electrooxidation: enhanced catalytic performance

Abstract(#br)PtRu bimetal is of particularly attractive in various electrocatalytic reactions owing to its synergistic effect, ligand effect and strain effect. Here, PtRu nanoalloy supported on porous graphitic carbon (PC) has been successfully prepared via a very facile method involving co-reduction the precursors of Pt and Ru at 300 °C by H 2 (PtRu/PCL) followed by thermal treatment at high temperature (700 °C, PtRu/PC–H). Specifically, the electrocatalytic performance of PtRu/PC nanoalloy could be dramatically enhanced through high-temperature annealing. This strategy has synthesized smaller Pt and PtRu nanoparticles (ca. L and Pt/PC nanocatalysts. The mass activity and specific activity on PtRu/PC–H nanoalloy can be increased to 1674.2 mA mg −1 Pt and 4.4 mA cm −2 for MOR, it is 4.08 and 8.80 times higher than that of the Pt/PC nanocatalyst, respectively. From in-situ FTIR spectra, we can discover PtRu/PC–H nanoalloy generates CO 2 at a lower potential of −150 mV than those on PtRu/PC–L (0 mV) and Pt/PC (50 mV) nanocatalysts, dramatically improves the ability of cleavage C–H bond and alleviates the CO ads poisoning on active sites. The PtRu/PCH nanocatalyst exhibits maximum power density of 83.7 mW cm −2 in single methanol fuel cell test, which more than threefold than that of commercial Pt/C as the anode catalyst. Those experimental results open an effective and clean avenue in the development and preparation of high-performance Pt-based nanocatalysts for direct methanol fuel cells

Energy Saving Simulation of Phase Change Materials in the Enclosure Structure of Archives Warehouse in Different Climatic Regions

Different climates in different regions have an important influence on the latent heat performance of PCMs, especially outdoor temperature and solar irradiance. This paper describes the addition of PCMs outside the archives warehouse in Guangzhou and Lhasa, and the temperature change and energy conservation of the exterior enclosure of the warehouse in summer and winter. In typical summer days in Guangzhou, PCMs with a phase change temperature of 30°C should be added to reduce the indoor cooling load by 23.91%. In typical winter days in Lhasa, PCMs with a phase change temperature of 8°C should be added, which can reduce the indoor heat load by 17.28%

Improving keystroke dynamics authentication system via multiple feature fusion scheme

This paper reports the performance and effect of diverse keystroke features combination on keystroke dynamic authentication system by using fusion scheme. First of all, four types of keystroke features are acquired from our collected dataset, later then transformed into similarity scores by the use of Gaussian Probability Density Function (GPD) and Direction Similarity Measure (DSM). Next, three fusion schemes are introduced to merge the scores pairing with six fusion rules. Result shows that the finest performance is obtained by the combination of both dwell time and flight time collectively. Finally, this experiment also investigates the effect of using larger dataset on performance, which turns out to be rather consistent. © 2012 IEEE

A survey of keystroke dynamics biometrics

Research on keystroke dynamics biometrics has been increasing, especially in the last decade. The main motivation behind this effort is due to the fact that keystroke dynamics biometrics is economical and can be easily integrated into the existing computer security systems with minimal alteration and user intervention. Numerous studies have been conducted in terms of data acquisition devices, feature representations, classification methods, experimental protocols, and evaluations. However, an up-to-date extensive survey and evaluation is not yet available. The objective of this paper is to provide an insightful survey and comparison on keystroke dynamics biometrics research performed throughout the last three decades, as well as offering suggestions and possible future research directions

A Mild Aqueous Sonogashira Reaction as a Fluorescent Labeling Strategy for 5-Bromide-2′-Deoxyuridine

C5-modified uridines are a valuable class of nucleoside analogues, both as potent chemotherapy agents and through their use as the conjunction site in DNA labeling strategies. As an important C5-modified uridine, BrdU has been used in cell proliferation assays since the 1980s. Currently, the detection of BrdU relies on traditional immunostaining; however, this approach has its limitations. Thus, it is desirable, albeit difficult, to develop chemistry methods to fluorescently label BrdU in a cellular context. In the present study, we report our efforts toward developing a robust chemistry methodology for BrdU fluorescent labeling. The Sonogashira reaction was chosen as the key reaction, and various alkynyl groups (aliphatic or aryl) containing fluorescent dyes were synthesized to cross-couple with BrdU. Various bases and catalyst systems were screened to evaluate the optimum conditions. A mild aqueous Sonogashira reaction (K2PdCl4, S-Phos, n-Bu4N+OH−, Sodium d-isoascorbate, EtOH/H2O = 1:1, 37 °C, Ar) was obtained to enable high-yielding BrdU fluorescent labeling

Hybrid "clusterbombs' as multifunctional nanoplatforms potentiate brain tumor immunotherapy

A hybrid clusterbomb' as a multifunctional nanoplatform (MPSDP-ZnO/Ag) was developed for the combined immunotherapy of intracranial tumors. MPSDP-ZnO/Ag possessed high antigen loading and well-defined hybrid nanostructures, and could trigger the cluster to bomb' in response to antigen-presenting cells for simultaneous antigen and adjuvant release. The in vitro and in vivo results confirmed significant antigen accumulation and enhanced cellular and humoral immunity. More importantly, our nanovaccines obviously prolonged the survival time of tumor-bearing mice without systemic toxicity

Spectrophotometric determination of trace amounts of selenium(IV) by catalytic kinetic method

2315-2317A spectrophotometric method for the determination of selenium(IV) is described, based on the selenium(IV)-catalyzed oxidation of methyl blue with KBrO3 in nitric acid medium. As the redox reaction proceeds, the blue colour of the dye is decolourized. LogA0/A shows a good linear relationship with the amount of selenium. The detection range of the method is 0-5 μg dm-3 with sensitivity of 0.3527 μg dm-3. The system is selective as most of the cations, viz, copper, potassium, iron , etc. can be tolerated during the determination of Se(IV). The method has been used to determine Se(IV) in Chinese herbal drugs

Design, Synthesis and Characterization of a Novel Type of Thermo-Responsible Phospholipid Microcapsule-Alginate Composite Hydrogel for Drug Delivery

Liposomes are extensively used in drug delivery, while alginates are widely used in tissue engineering. However, liposomes are usually thermally unstable and drug-leaking when in liquids, while the drug carriers made of alginates show low loading capacities when used for drug delivery. Herein, we developed a type of thermo-responsible liposome-alginate composite hydrogel (TSPMAH) by grafting thermo-responsive liposomes onto alginates by using Ca2+ mediated bonding between the phosphatidic serine (PS) in the liposome membrane and the alginate. The temperature-sensitivity of the liposomes was actualized by using phospholipids comprising dipalmitoylphosphatidylcholine (DPPC) and PS and the liposomes were prepared by a thin-film dispersion method. The TSPMAH was then successfully prepared by bridge-linking the microcapsules onto the alginate hydrogel via PS-Ca2+-Carboxyl-alginate interaction. Characterizations of the TSPMAH were carried out using scanning electron microscopy, transform infrared spectroscopy, and laser scanning confocal microscopy, respectively. Their rheological property was also characterized by using a rheometer. Cytotoxicity evaluations of the TSPMAH showed that the composite hydrogel was biocompatible, safe, and non-toxic. Further, loading and thermos-inducible release of model drugs encapsulated by the TSPMAH as a drug carrier system was also studied by making protamine-siRNA complex-carrying TSPMAH drug carriers. Our results indicated that the TSPMAH described herein has great potentials to be further developed into an intelligent drug delivery system