L2L_2 boosting in kernel regression

In this paper, we investigate the theoretical and empirical properties of $L_2$ boosting with kernel regression estimates as weak learners. We show that each step of $L_2$ boosting reduces the bias of the estimate by two orders of magnitude, while it does not deteriorate the order of the variance. We illustrate the theoretical findings by some simulated examples. Also, we demonstrate that $L_2$ boosting is superior to the use of higher-order kernels, which is a well-known method of reducing the bias of the kernel estimate.Comment: Published in at http://dx.doi.org/10.3150/08-BEJ160 the Bernoulli (http://isi.cbs.nl/bernoulli/) by the International Statistical Institute/Bernoulli Society (http://isi.cbs.nl/BS/bshome.htm

Biochemical Properties of a Decoy Oligodeoxynucleotide Inhibitor of STAT3 Transcription Factor.

Cyclic STAT3 decoy (CS3D) is a second-generation, double-stranded oligodeoxynucleotide (ODN) that mimics a genomic response element for signal transducer and activator of transcription 3 (STAT3), an oncogenic transcription factor. CS3D competitively inhibits STAT3 binding to target gene promoters, resulting in decreased expression of proteins that promote cellular proliferation and survival. Previous studies have demonstrated antitumor activity of CS3D in preclinical models of solid tumors. However, prior to entering human clinical trials, the efficiency of generating the CS3D molecule and its stability in biological fluids should be determined. CS3D is synthesized as a single-stranded ODN and must have its free ends ligated to generate the final cyclic form. In this study, we report a ligation efficiency of nearly 95 percent. The ligated CS3D demonstrated a half-life of 7.9 h in human serum, indicating adequate stability for intravenous delivery. These results provide requisite biochemical characterization of CS3D that will inform upcoming clinical trials

High-throughput and label-free blood-on-a-chip for malaria diagnosis

The malaria parasite Plasmodium falciparum (Pf) changes the structure and mechanical properties of red blood cells (RBCs). These changes decrease deformability and increase cytoadherence of Pf-infected RBCs to the vascular endothelium, eventually leading to flow occlusions in capillary vessels. In this study, to detect Pf-infected RBCs effectively, deformability and viscosity of blood sample are measured simultaneously and indirectly by quantifying blood flow in a microfluidic device. The microfluidic device is designed by mimicking a Wheatstone-bridge electric circuit. To measure RBC deformability, a deformability assessment chamber (DAC) at the left lower side channel has parallel microfluidic filters. After delivering blood sample and 1x PBS solution at the same flow rate, hemodynamic properties are measured using a time-resolved microparticle image velocimetry technique. Blood volume delivered into the DAC for 200 s is evaluated as a deformability index. Subsequently, blood viscosity is quantified by monitoring blood-filled width of parallel flows in the microfluidic device. The proposed method is applied to evaluate variations in biophysical properties of blood samples partially mixed with normal RBCs and hardened RBCs. As a result, RBC deformability is more effective than blood viscosity in the detection of blood samples with hardened RBC volume fraction of 5%. The microfluidic device is also applied to detect Pf-infected RBCs. When parasitemia is greater than 0.515% for ring stage, 0.0544% for trophozoite stage, and 0.0054% for schizont stage, the measured velocity fields show unstable behavior because of cytoadherence of Pf-infected RBCs. Blood volume delivered into the DAC significantly decreases with increasing parasitemia. The experimental method proposed in this study can detect Pf-infected RBCs with good accuracy.1113Ysciescopu

Performance of a prototype active veto system using liquid scintillator for a dark matter search experiment

We report the performance of an active veto system using a liquid scintillator with NaI(Tl) crystals for use in a dark matter search experiment. When a NaI(Tl) crystal is immersed in the prototype detector, the detector tags 48% of the internal K-40 background in the 0-10 keV energy region. We also determined the tagging efficiency for events at 6-20 keV as 26.5 +/- 1.7% of the total events, which corresponds to 0.76 +/- 0.04 events/keV/kg/day. According to a simulation, approximately 60% of the background events from U, Th, and K radioisotopes in photomultiplier tubes are tagged at energies of 0-10 keV. Full shielding with a 40-cm-thick liquid scintillator can increase the tagging efficiency for both the internal K-40 and external background to approximately 80%.Comment: Submitted to Nuclear Instruments and Methods in Physics Research Section

Symmetry-Breaking Motility

Locomotion of bacteria by actin polymerization, and in vitro motion of spherical beads coated with a protein catalyzing polymerization, are examples of active motility. Starting from a simple model of forces locally normal to the surface of a bead, we construct a phenomenological equation for its motion. The singularities at a continuous transition between moving and stationary beads are shown to be related to the symmetries of its shape. Universal features of the phase behavior are calculated analytically and confirmed by simulations. Fluctuations in velocity are shown to be generically non-Maxwellian and correlated to the shape of the bead.Comment: 4 pages, 2 figures, REVTeX; formatting of references correcte

The Potential Use of Ssr Markers to Support the Morphological Identification of Indonesian Mungbean Varieties

Mungbean varieties were mainly characterized based on morphological traits. Molecular genetic approach is expected to help the breeder in identification of mungbean varieties in more detail and to protect intellectual property right. This study aimed to identify Indonesian mungbean varieties based on DNA fingerprint profile using a marker set to support morphological characters. A total of 22 Indonesian mungbean accessions were characterized based on 21 morphological traits and 55 simple sequence repeats (SSRs) primers. Of the total 22 mungbean varieties used in the present study, 16 varieties were improved varieties and remaining six varieties were local varieties originated from Java, Nusa Tenggara and Sulawesi collected in GeneBank of ICABIOGRAD. The results showed that the 21 morphological characters were not sufficient to differentiate 22 mungbean varieties, while SSR analysis revealed that eight multi-alleles markers and high polymorphic information content (PIC) values have been successfully selected for varietal identification. The selected markers enabled to differentiate each mungbean variety according to their genetic marker with the lowest distance of 0.125, demonstrating the robustness of the selected marker set as a tool to identify a specific DNA fingerprint profile as a varietal identity (ID). The genetic identity of a variety was shown by digital barcoding which represented a series of alleles produced by corresponding markers. The DNA fingerprint profile of each variety would be beneficial as reference identities of a mungbean variety

Three-dimensional structures of the tracheal systems of Anopheles sinensis and Aedes togoi pupae

Mosquitoes act as a vector for the transmission of disease. The World Health Organization has recommended strict control of mosquito larvae because of their few, fixed, and findable features. The respiratory system of mosquito larvae and pupae in the water has a weak point. As aquatic organisms, mosquito larvae and pupae inhale atmosphere oxygen. However, the mosquito pupae have a non-feeding stage, unlike the larvae. Therefore, detailed study on the tracheal system of mosquito pupae is helpful for understanding their survival strategy. In this study, the three-dimensional (3D) structures of the tracheal systems of Anopheles sinensis and Aedes togoi pupae were comparatively investigated using synchrotron X-ray microscopic computed tomography. The respiratory frequencies of the dorsal trunks were also investigated. Interestingly, the pupae of the two mosquito species possess special tracheal systems of which the morphological and functional features are distinctively different. The respiratory frequency of Ae. togoi is higher than that of An. sinensis. These differences in the breathing phenomena and 3D structures of the respiratory systems of these two mosquito species provide an insight into the tracheal systems of mosquito pupae. ? 2017 The Author(s).111Ysciescopu