Two Improved Multiple-Differential Collision Attacks

In CHES 2008, Bogdanov proposed multiple-differential collision attacks which could be applied to the power analysis attacks on practical cryptographic systems. However, due to the effect of countermeasures on FPGA, there are some difficulties during the collision detection, such as local high noise and the lack of sampling points. In this paper, keypoints voting test is proposed for solving these problems, which can increase the success ratio from 35% to 95% on the example of one implementation. Furthermore, we improve the ternary voting test of Bogdanov, which can improve the experiment efficiency markedly. Our experiments show that the number of power traces required in our attack is only a quarter of the requirement of traditional attack. Finally, some alternative countermeasures against our attacks are discussed

Hydroxyapatite Film Coating by Er:YAG Pulsed Laser Deposition Method for the Repair of Enamel Defects

There are treatments available for enamel demineralization or acid erosion, but they have limitations. We aimed to manufacture a device that could directly form a hydroxyapatite (HAp) film coating on the enamel with a chairside erbium-doped yttrium aluminum garnet (Er:YAG) laser using the pulsed laser deposition (PLD) method for repairing enamel defects. We used decalcified bovine enamel specimens and compacted α-tricalcium phosphate (α-TCP) as targets of Er:YAG-PLD. With irradiation, an α-TCP coating layer was immediately deposited on the specimen surface. The morphological, mechanical, and chemical characteristics of the coatings were evaluated using scanning electron microscopy (SEM), scanning probe microscopy (SPM), X-ray diffractometry (XRD), and a micro-Vickers hardness tester. Wear resistance, cell attachment of the HAp coatings, and temperature changes during the Er:YAG-PLD procedure were also observed. SEM demonstrated that the α-TCP powder turned into microparticles by irradiation. XRD peaks revealed that the coatings were almost hydrolyzed into HAp within 2 days. Micro-Vickers hardness indicated that the hardness lost by decalcification was almost recovered by the coatings. The results suggest that the Er:YAG-PLD technique is useful for repairing enamel defects and has great potential for future clinical applications

An Efficient BScan-Sample-Based Sigma Delta Beamformer for Medical Ultrasound Imaging

Sigma Delta beamforming is a promising technique for small analog front-end(AFE) of the medical ultrasound imaging system. Nonetheless, the high data rate from the EA modulator in the AFE and the high-Q reconstruction filter put harsh requirements on the digital beamforming circuits. Although the BScan-sample-based Sigma Delta beamformer structure with FIR reconstruction filter reduces the speed requirement on multipliers so as to make the Sigma Delta beamformer implementable in conventional digital platforms, it still requires large area for high-speed adders. In this work, a new BScan-sample-based Sigma Delta beamformer structure with IIR reconstruction fitlter is developed. The new structure greatly reduces the hardware cost. Both Sigma Delta beamformers are implemented in FPGAs and digital ICs. The new beamformer is 8 times smaller than the FIR beamformer. For a 128-element, 5MHz ultrasound medical imaging system with 256 beamformers, the new Sigma Delta beamformer can be implemented with 2 FPGA chips or a 5.2mmx5.2mm digital IC in 0.18 mu m CMOS logic process

Effect of Hydroxyapatite Coating by Er: YAG Pulsed Laser Deposition on the Bone Formation Efficacy by Polycaprolactone Porous Scaffold

Composite scaffolds obtained by the combination of biodegradable porous scaffolds and hydroxyapatite with bone regeneration potential are feasible materials for bone tissue engineering. However, most composite scaffolds have been fabricated by complicated procedures or under thermally harsh conditions. We have previously demonstrated that hydroxyapatite coating onto various substrates under a thermally mild condition was achieved by erbium-doped yttrium aluminum garnet (Er: YAG) pulsed laser deposition (PLD). The purpose of this study was to prepare a polycaprolactone (PCL) porous scaffold coated with the hydroxyapatite by the Er: YAG-PLD method. Hydroxyapatite coating by the Er: YAG-PLD method was confirmed by morphology, crystallographic analysis, and surface chemical characterization studies. When cultured on PCL porous scaffold coated with hydroxyapatite, rat bone marrow-derived mesenchymal stem cells adhered, spread, and proliferated well. The micro-CT and staining analyses after the implantation of scaffold into the critical-sized calvaria bone defect in rats indicate that PCL porous scaffold coated with hydroxyapatite demonstrates accelerated and widespread bone formation. In conclusion, PCL porous scaffold coated with hydroxyapatite obtained by the Er: YAG-PLD method is a promising material in bone tissue engineering

Responses of growing‐season soil respiration to water and nitrogen addition as affected by grazing intensity

1. Most grasslands in the world, including the semi-arid steppe in China, are threatened by nitrogen deposition, precipitation change and livestock grazing, which greatly affect soil carbon processes (e.g. soil respiration). Although the individual effects of nitrogen deposition and precipitation change on soil respiration are well understood, how their effects on soil respiration are altered by different grazing intensities is unclear. 2. To determine how the effects of nitrogen deposition and precipitation change on soil respiration are affected by grazing intensity, we conducted an experiment in a semi-arid steppe involving areas that experienced 10 years of no, light, moderate or heavy grazing. These areas were treated with water addition (110 mm, 30% of the mean annual precipitation) and nitrogen addition (10.5 g m(-2) year(-1)). 3. Our results showed that relative to no grazing, grazing decreased growing-season soil respiration by 10%-19%. The decline in soil respiration was mainly via its negative effects on above-ground net primary productivity (ANPP) and the fungi: bacteria ratio with light grazing, mainly via its negative effects on ANPP and leaf nitrogen content with moderate grazing, and mainly via its negative effects on ANPP, root biomass, microbial biomass and the fungi: bacteria ratio with heavy grazing. 4. Across all grazing intensities, both water and water+nitrogen addition increased growing-season soil respiration, whereas nitrogen addition decreased growing-season soil respiration. Water addition increased growing-season soil respiration mostly via its positive effect on ANPP with no grazing and with low grazing, and mostly via its positive effects on both plant and microbial variables with moderate and heavy grazing. The pathways determining the nitrogen addition-induced decline in growing-season soil respiration were the same within each of the four levels of grazing and mostly resulted from its negative effect on microbial variables. 5. Our results indicate that the effects of climate change on growing-season soil respiration and other soil carbon processes in grasslands depend on grazing intensity. The findings suggest that grazing intensity should be considered in future manipulation experiments and should be included in carbon models to accurately simulate soil carbon dynamics under scenarios of climate change in grassland ecosystems

Responses of growing-season soil respiration to water and nitrogen addition as affected by grazing intensity

1. Most grasslands in the world, including the semi-arid steppe in China, are threatened by nitrogen deposition, precipitation change and livestock grazing, which greatly affect soil carbon processes (e.g. soil respiration). Although the individual effects of nitrogen deposition and precipitation change on soil respiration are well understood, how their effects on soil respiration are altered by different grazing intensities is unclear. 2. To determine how the effects of nitrogen deposition and precipitation change on soil respiration are affected by grazing intensity, we conducted an experiment in a semi-arid steppe involving areas that experienced 10 years of no, light, moderate or heavy grazing. These areas were treated with water addition (110 mm, 30% of the mean annual precipitation) and nitrogen addition (10.5 g m(-2) year(-1)). 3. Our results showed that relative to no grazing, grazing decreased growing-season soil respiration by 10%-19%. The decline in soil respiration was mainly via its negative effects on above-ground net primary productivity (ANPP) and the fungi: bacteria ratio with light grazing, mainly via its negative effects on ANPP and leaf nitrogen content with moderate grazing, and mainly via its negative effects on ANPP, root biomass, microbial biomass and the fungi: bacteria ratio with heavy grazing. 4. Across all grazing intensities, both water and water+nitrogen addition increased growing-season soil respiration, whereas nitrogen addition decreased growing-season soil respiration. Water addition increased growing-season soil respiration mostly via its positive effect on ANPP with no grazing and with low grazing, and mostly via its positive effects on both plant and microbial variables with moderate and heavy grazing. The pathways determining the nitrogen addition-induced decline in growing-season soil respiration were the same within each of the four levels of grazing and mostly resulted from its negative effect on microbial variables. 5. Our results indicate that the effects of climate change on growing-season soil respiration and other soil carbon processes in grasslands depend on grazing intensity. The findings suggest that grazing intensity should be considered in future manipulation experiments and should be included in carbon models to accurately simulate soil carbon dynamics under scenarios of climate change in grassland ecosystems

Responses of growing-season soil respiration to water and nitrogen addition as affected by grazing intensity

1. Most grasslands in the world, including the semi-arid steppe in China, are threatened by nitrogen deposition, precipitation change and livestock grazing, which greatly affect soil carbon processes (e.g. soil respiration). Although the individual effects of nitrogen deposition and precipitation change on soil respiration are well understood, how their effects on soil respiration are altered by different grazing intensities is unclear. 2. To determine how the effects of nitrogen deposition and precipitation change on soil respiration are affected by grazing intensity, we conducted an experiment in a semi-arid steppe involving areas that experienced 10 years of no, light, moderate or heavy grazing. These areas were treated with water addition (110 mm, 30% of the mean annual precipitation) and nitrogen addition (10.5 g m(-2) year(-1)). 3. Our results showed that relative to no grazing, grazing decreased growing-season soil respiration by 10%-19%. The decline in soil respiration was mainly via its negative effects on above-ground net primary productivity (ANPP) and the fungi: bacteria ratio with light grazing, mainly via its negative effects on ANPP and leaf nitrogen content with moderate grazing, and mainly via its negative effects on ANPP, root biomass, microbial biomass and the fungi: bacteria ratio with heavy grazing. 4. Across all grazing intensities, both water and water+nitrogen addition increased growing-season soil respiration, whereas nitrogen addition decreased growing-season soil respiration. Water addition increased growing-season soil respiration mostly via its positive effect on ANPP with no grazing and with low grazing, and mostly via its positive effects on both plant and microbial variables with moderate and heavy grazing. The pathways determining the nitrogen addition-induced decline in growing-season soil respiration were the same within each of the four levels of grazing and mostly resulted from its negative effect on microbial variables. 5. Our results indicate that the effects of climate change on growing-season soil respiration and other soil carbon processes in grasslands depend on grazing intensity. The findings suggest that grazing intensity should be considered in future manipulation experiments and should be included in carbon models to accurately simulate soil carbon dynamics under scenarios of climate change in grassland ecosystems

Hydroxyapatite Film Coating by Er:YAG Pulsed Laser Deposition Method for the Repair of Enamel Defects

There are treatments available for enamel demineralization or acid erosion, but they have limitations. We aimed to manufacture a device that could directly form a hydroxyapatite (HAp) film coating on the enamel with a chairside erbium-doped yttrium aluminum garnet (Er:YAG) laser using the pulsed laser deposition (PLD) method for repairing enamel defects. We used decalcified bovine enamel specimens and compacted α-tricalcium phosphate (α-TCP) as targets of Er:YAG-PLD. With irradiation, an α-TCP coating layer was immediately deposited on the specimen surface. The morphological, mechanical, and chemical characteristics of the coatings were evaluated using scanning electron microscopy (SEM), scanning probe microscopy (SPM), X-ray diffractometry (XRD), and a micro-Vickers hardness tester. Wear resistance, cell attachment of the HAp coatings, and temperature changes during the Er:YAG-PLD procedure were also observed. SEM demonstrated that the α-TCP powder turned into microparticles by irradiation. XRD peaks revealed that the coatings were almost hydrolyzed into HAp within 2 days. Micro-Vickers hardness indicated that the hardness lost by decalcification was almost recovered by the coatings. The results suggest that the Er:YAG-PLD technique is useful for repairing enamel defects and has great potential for future clinical applications

RANGE: Gene Transfer of Reversibly Controlled Polycistronic Genes

We developed a single vector recombinant adeno-associated viral (rAAV) expression system for spatial and reversible control of polycistronic gene expression. Our approach (i) integrates the advantages of the tetracycline (Tet)-controlled transcriptional silencer tTSKid and the self-cleaving 2A peptide bridge, (ii) combines essential regulatory components as an autoregulatory loop, (iii) simplifies the gene delivery scheme, and (iv) regulates multiple genes in a synchronized manner. Controlled by an upstream Tet-responsive element (TRE), both the ubiquitous chicken β-actin promoter (CAG) and the neuron-specific synapsin-1 promoter (Syn) could regulate expression of tTSKid together with two 2A-linked reporter genes. Transduction in vitro exhibited maximally 50-fold regulation by doxycycline (Dox). Determined by gene delivery method as well as promoter, highly specific tissues were transduced in vivo. Bioluminescence imaging (BLI) visualized reversible “ON/OFF” gene switches over repeated “Doxy-Cycling” in living mice. Thus, the reversible rAAV-mediated N-cistronic gene expression system, termed RANGE, may serve as a versatile tool to achieve reversible polycistronic gene regulation for the study of gene function as well as gene therapy