A Designated Query Protocol for Serverless Mobile RFID Systems with Reader and Tag Privacy

Recently, a new type of Radio Frequency IDentification (RFID) system with mobile readers is introduced. In such a system, it is more desirable for mobile readers to identify tags without a back-end server, and thus it is frequently referred as a serverless mobile RFID system. In this paper, we formalize a serverless mobile RFID system model and propose a new encryption-based system that preserves the privacy of both tags and readers in the model. In addition, we define a new adversary model for the system model and show the security of the proposed system. Throughout comparisons between ours and the other alternatives, we show that our proposed system provides a stronger reader privacy and robustness against a reader forgery attack than the competitors.     

Understanding Natural Science Based on Abductive Inference: Continental Drift

This study aims to understand scientific inference for the evolutionary procedure of Continental Drift based on abductive inference, which is important for creative inference and scientific discovery during problem solving. We present the following two research problems: (1) we suggest a scientific inference procedure as well as various strategies and a criterion for choosing hypotheses over other competing or previous hypotheses; aspects of this procedure include puzzling observation, abduction, retroduction, updating, deduction, induction, and recycle; and (2) we analyze the “theory of continental drift” discovery, called the Earth science revolution, using our multistage inference procedure. Wegener’s Continental Drift hypothesis had an impact comparable to the revolution caused by Darwin’s theory of evolution in biology. Finally, the suggested inquiry inference model can provide us with a more consistent view of science and promote a deeper understanding of scientific concepts.     

The inner jet of an active galactic nucleus as revealed by a radio-to-gamma-ray outburst

Blazars are the most extreme active galactic nuclei. They possess oppositely directed plasma jets emanating at near light speeds from accreting supermassive black holes. According to theoretical models, such jets are propelled by magnetic fields twisted by differential rotation of the black hole's accretion disk or inertial-frame-dragging ergosphere. The flow velocity increases outward along the jet in an acceleration and collimation zone containing a coiled magnetic field. Detailed observations of outbursts of electromagnetic radiation, for which blazars are famous, can potentially probe the zone. It has hitherto not been possible to either specify the location of the outbursts or verify the general picture of jet formation. Here we report sequences of high-resolution radio images and optical polarization measurements of the blazar BL Lacertae. The data reveal a bright feature in the jet that causes a double flare of radiation from optical frequencies to TeV gamma-ray energies, as well as a delayed outburst at radio wavelengths. We conclude that the event starts in a region with a helical magnetic field that we identify with the acceleration and collimation zone predicted by the theories. The feature brightens again when it crosses a standing shock wave corresponding to the bright 'core' seen on the images.     

Control of plant germline proliferation by SCF(FBL17) degradation of cell cycle inhibitors

Flowering plants possess a unique reproductive strategy, involving double fertilization by twin sperm cells. Unlike animal germ lines, the male germ cell lineage in plants only forms after meiosis and involves asymmetric division of haploid microspores, to produce a large, non-germline vegetative cell and a germ cell that undergoes one further division to produce the twin sperm cells. Although this switch in cell cycle control is critical for sperm cell production and delivery, the underlying molecular mechanisms are unknown. Here we identify a novel F-box protein of Arabidopsis thaliana, designated FBL17 (F-box-like 17), that enables this switch by targeting the degradation of cyclin-dependent kinase A;1 inhibitors specifically in male germ cells. We show that FBL17 is transiently expressed in the male germ line after asymmetric division and forms an SKP1-Cullin1-F-box protein (SCF) E3 ubiquitin ligase complex (SCF(FBL17)) that targets the cyclin-dependent kinase inhibitors KRP6 and KRP7 for proteasome-dependent degradation. Accordingly, the loss of FBL17 function leads to the stabilization of KRP6 and inhibition of germ cell cycle progression. Our results identify SCF(FBL17) as an essential male germ cell proliferation complex that promotes twin sperm cell production and double fertilization in flowering plants.     

Reversal of pathological pain through specific spinal GABAA receptor subtypes

Inflammatory diseases and neuropathic insults are frequently accompanied by severe and debilitating pain, which can become chronic and often unresponsive to conventional analgesic treatment. A loss of synaptic inhibition in the spinal dorsal horn is considered to contribute significantly to this pain pathology. Facilitation of spinal gamma-aminobutyric acid (GABA)ergic neurotransmission through modulation of GABA(A) receptors should be able to compensate for this loss. With the use of GABA(A)-receptor point-mutated knock-in mice in which specific GABA(A) receptor subtypes have been selectively rendered insensitive to benzodiazepine-site ligands, we show here that pronounced analgesia can be achieved by specifically targeting spinal GABA(A) receptors containing the alpha2 and/or alpha3 subunits. We show that their selective activation by the non-sedative ('alpha1-sparing') benzodiazepine-site ligand L-838,417 (ref. 13) is highly effective against inflammatory and neuropathic pain yet devoid of unwanted sedation, motor impairment and tolerance development. L-838,417 not only diminished the nociceptive input to the brain but also reduced the activity of brain areas related to the associative-emotional components of pain, as shown by functional magnetic resonance imaging in rats. These results provide a rational basis for the development of subtype-selective GABAergic drugs for the treatment of chronic pain, which is often refractory to classical analgesics.     

Sojucktang induces apoptosis via loss of mitochondrial membrane potential and caspase-3 activation in KLE human endometrial cancer cells

Sojucktang （SJT） has long been used for the treatment of endometrial diseases in Korea. However, the mechanisms responsible for the SJT-induced apoptosis in endometrial cancer cells remain unclear. In the present study, SJT was demonstrated to show cytotoxic effect and induce apoptotic cell death via mitochondrial regulation in KLE endometrial cancer cells. Linderae Radix, Glycyrrhizae Radix, Zedoariae Rhizoma, Trogopterorum Faeces and Agelicae Gigantis Radix were found to be the potent constituent herbs of SJT to significantly decrease the viability of KLE cells by a tetra zolium salt （XTT） assay. Apoptotic bodies were observed in SJT-treated KLE cells by 4′-6-diamidino-2-phenylindole （DAPI） and TdT-mediated-dUTP nick-end labeling （TUNEL） assay. SJT also increased sub-G1 DNA contents of the cell cycle undergoing apoptosis in a dose-dependent manner. Furthermore, it was observed that SJT activated caspase-3 and cleaved poly （ADP-ribose） polymerase （PARP）, and decreased mitochondrial membrane potential in a dose-dependent manner. Taken together, this study shows that SJT exerts anti-tumor activity against KLE endometrial cancer cells via mitochondrial dependent apoptosis induction.     

Folding-driven synthesis of oligomers.

The biological function of biomacromolecules such as DNA and enzymes depends on their ability to perform and control molecular association, catalysis, self-replication or other chemical processes. In the case of proteins in particular, the dependence of these functions on the three-dimensional protein conformation is long known and has inspired the development of synthetic oligomers and polymers with the capacity to fold in a controlled manner, but it remains challenging to design these so-called 'foldamers' so that they are capable of inducing or controlling chemical processes and interactions. Here we show that the stability gained from folding can be used to control the synthesis of oligomers from short chain segments reversibly ligated through an imine metathesis reaction. That is, folding shifts the ligation equilibrium in favour of conformationally ordered sequences, so that oligomers having the most stable solution structures form preferentially. Crystallization has previously been used to shift an equilibrium in order to indirectly influence the synthesis of small molecules, but the present approach to selectively prepare macromolecules with stable conformations directly connects folding and synthesis, emphasizing molecular function rather than structure in polymer synthesis.     

Systematic pathway analysis using high-resolution fitness profiling of combinatorial gene deletions

Systematic genetic interaction studies have illuminated many cellular processes. Here we quantitatively examine genetic interactions among 26 Saccharomyces cerevisiae genes conferring resistance to the DNA-damaging agent methyl methanesulfonate (MMS), as determined by chemogenomic fitness profiling of pooled deletion strains. We constructed 650 double-deletion strains, corresponding to all pairings of these 26 deletions. The fitness of single- and double-deletion strains were measured in the presence and absence of MMS. Genetic interactions were defined by combining principles from both statistical and classical genetics. The resulting network predicts that the Mph1 helicase has a role in resolving homologous recombination-derived DNA intermediates that is similar to (but distinct from) that of the Sgs1 helicase. Our results emphasize the utility of small molecules and multifactorial deletion mutants in uncovering functional relationships and pathway order.