Yuanyuan Huang

In this paper, we propose a method to design the pseudorandom number generator using three kinds of four-wing memristive hyperchaotic systems with different dimensions as multientropy sources. The principle of this method is to obtain pseudorandom numbers with good randomness by coupling XOR operation on the three kinds of FWMHSs with different dimensions. In order to prove its potential application in secure communication, the security of PRNG based on this scheme is analyzed from the perspective of cryptography. In addition, PRNG has passed the NIST 800.22 and ENT test, which shows that PRNG has good statistical characteristics. Finally, an image encryption algorithm based on PRNG is adopted. In the encryption algorithm, the optimized Arnold matrix scrambling method and the diffusion processing based on XOR are used to obtain the final encrypted image. Through the evaluation of encryption performance, it is concluded that there is no direct relationship between the pristine image and encrypted image. The results show that the proposed image encryption scheme has good statistical output characteristics and security performance in line with cryptography.

As patient autonomy expands, a highly controversial issue has emerged. Should the advance directives of refusing life-saving treatments or requesting euthanasia of persons with dementia who express changed minds or are often in a happy state be fulfilled? There are two autonomy-related positions. The mainstream position in philosophical discussions supports the priority of ADs based on precedent autonomy. Buchanan and Brock, and Dworkin represent this view. The other position supports the priority of PWDs’ current wishes based on minimal autonomy represented by Jaworska. By rethinking the theoretical and practical challenges of the two positions and their arguments respectively, the paper concludes that in such a scenario, the priority of ADs is morally indefensible, and it is also challenging to establish minimal autonomy defend the moral priority of PWDs’ current wishes. For PWDs whose past values, beliefs, and preferences fade away but who retain apparent intrinsic sentience of well-being, a modified defined quality-of-life approach serves as another reasonable basis in their medical decision-making, and the ADs and the QoL should be further merged to reduce the uncertainty of the grey zone.

Cooley's argument that persons with pre‐dementia have a Kantian duty to die has led to much debate. Cooley gives two reasons for his claim, the first being that a person with pre‐dementia should end his/her life when he/she will inevitably and irreversibly lose rationality and be unable to live morally as a result. This paper argues that this reason derives from an unsubstantiated premise and general confusion regarding the condition for a Kantian duty to die. Rather, a close reading of Kant reveals that such a condition occurs when a person confronts an external handicap that does not undermine his/her rational ability but deprives him/her of the possibility of living the way a person should. People do not confront this experience with progressive dementia. The other reason Cooley proposes is that a person should not allow their continued existence to become a burden to others. This claim partly stems from a radical interpretation of a case discussed by Kant and is partly based on a misuse of Kant's formulation of humanity. Based on a prudent inference from Kantian ethics, this article argues against Cooley that persons with pre‐dementia have no Kantian duty to die.

In recent years, the research of chaos theory has developed from simple cognition and analysis to practical engineering application. In particular, hyperchaotic systems with more complex and changeable chaotic characteristics are more sensitive and unpredictable, so they are widely used in more fields. In this paper, two important engineering applications based on hyperchaos pseudorandom number generator and image encryption are studied. Firstly, the coupling 6D memristive hyperchaotic system and a 2D SF-SIMM discrete hyperchaotic mapping are used as the double entropy source structure. The double entropy source structure can realize a new PRNG that meets the security requirements, which can pass the NIST statistical test when the XOR postprocessing method is used. Secondly, based on the double entropy source structure, a new image encryption algorithm is proposed. The algorithm uses the diffusion-scrambling-diffusion encryption scheme to realize the conversion from the original plaintext image to the ciphertext image. Finally, we analyze the security of the proposed PRNG and image encryption mechanism, respectively. The results show that the proposed PRNG has good statistical output characteristics and the proposed image encryption scheme has high security, so they can be effectively applied in the field of information security and encryption system.

Due to their unique properties, copper-based nanopesticides are emerging in the market. Thus, understanding their effect on crop plants is very important. Metabolomics can capture a snapshot of cellular metabolic responses to a stressor. We selected maize and cucumber as model plants for exposure to different doses of Cu2 nanopesticide. GC-TOF-MS-based metabolomics was employed to determine the metabolic responses of these two species. Results revealed significant differences in metabolite profile changes between maize and cucumber. Furthermore, the Cu2 nanopesticide induced metabolic reprogramming in both species, but in different manners. In maize, several intermediate metabolites of the glycolysis pathway and tricarboxylic acid cycle were up-regulated, indicating the energy metabolism was activated. In addition, the levels of aromatic compounds and their precursors were enhanced, indicating the activation of shikimate-phenylpropanoid biosynthesis in maize leaves, which is an antioxidant defense-related pathway. In cucumber, arginine and proline metabolic pathways were the most significantly altered pathway. Both species exhibited altered levels of fatty acids and polysaccharides, suggesting the cell membrane and cell wall composition may change in response to Cu2 nanopesticide. Thus, metabolomics helps to deeply understand the differential response of these plants to the same nanopesticide stressor.

Deception is common in dementia care, although its moral legitimacy is questionable. This paper conceptually clarifies when does dementia care involve deception and argues that care ethics is an appropriate ethical framework to guide dementia care compared with the mainstream ethical theories that emphasize abilities. From a perspective of care ethics, this paper claims that morally defensible deception is context-specific, embodied as a caring process that needs to be identified through instant, creative and interactive care procedures. According to this argument, it further analyses and concludes the moral rationality of deception in five common cases. While deception is morally justified in many situations, another concern is that it is usually not the last resort but a means of convenience. As the ability to interact, autonomy and dignity of persons with dementia (PWDs) are generally ignored; nurses need more training and education to master the essential procedures to ensure that the value of authenticity and autonomy is maintained and considered throughout dementia care.

© 2016 American Chemical Society.Layered transition metal chalcogenides with large spin orbit coupling have recently sparked much interest due to their potential applications for electronic, optoelectronic, spintronics, and valleytronics. However, most current understanding of the electronic structure near band valleys in momentum space is based on either theoretical investigations or optical measurements, leaving the detailed band structure elusive. For example, the exact position of the conduction band valley of bulk MoS2 remains controversial. Here, using angle-resolved photoemission spectroscopy with submicron spatial resolution, we systematically imaged the conduction/valence band structure evolution across representative chalcogenides MoS2, WS2, and WSe2, as well as the thickness dependent electronic structure from bulk to the monolayer limit. These results establish a solid basis to understand the underlying valley physics of these materials, and also provide a link between chalcogenide electronic band structure and their physical properties for potential valleytronics applications.

To better determine the history of modern birds, we performed a genome-scale phylogenetic analysis of 48 species representing all orders of Neoaves using phylogenomic methods created to handle genome-scale data.We recovered a highly resolved tree that confirms previously controversial sister or close relationships.We identified the first divergence in Neoaves, two groups we named Passerea and Columbea, representing independent lineages of diverse and convergently evolved land and water bird species. Among Passerea, we infer the common ancestor of core landbirds to have been an apex predator and confirm independent gains of vocal learning. Among Columbea, we identify pigeons and flamingoes as belonging to sister clades. Even with whole genomes, some of the earliest branches in Neoaves proved challenging to resolve, which was best explained by massive protein-coding sequence convergence and high levels of incomplete lineage sorting that occurred during a rapid radiation after the Cretaceous-Paleogene mass extinction event about 66 million years ago.