A complete characterization of statistical query learning with applications to evolvability

Statistical query (SQ) learning model of Kearns is a natural restriction of the PAC learning model in which a learning algorithm is allowed to obtain estimates of statistical properties of the examples but cannot see the examples themselves (Kearns, 1998 [29]). We describe a new and simple characterization of the query complexity of learning in the SQ learning model. Unlike the previously known bounds on SQ learning (Blum, et al., 1994; Bshouty and Feldman, 2002; Yang, 2005; Balcázar, et al., 2007; Simon, 2007 [9], [11], [42], [3], [37]) our characterization preserves the accuracy and the efficiency of learning. The preservation of accuracy implies that our characterization gives the first characterization of SQ learning in the agnostic learning framework of Haussler (1992) [23] and Kearns, Schapire and Sellie (1994) [31]. The preservation of efficiency is achieved using a new boosting technique and allows us to derive a new approach to the design of evolution algorithms in Valiant?s model of evolvability (Valiant, 2009 [40]). We use this approach to demonstrate the existence of a large class of monotone evolution algorithms based on square loss performance estimation. These results differ significantly from the few known evolution algorithms and give evidence that evolvability in Valiant?s model is a more versatile phenomenon than there had been previous reason to suspect.     

Statistical and electrical properties of the conduction electrons of a metal nanosphere in the region of metal-insulator transition

Statistical and electrical properties of the conduction electrons of a silver or gold sphere with a radius from 1 to 2 nm are shown to differ drastically from the properties of electrons in a bulk metal sample. If the radius of a noble metal sphere decreases from 10 to 1 nm, its conductivity oscillates around the bulk metal value with increasing amplitude and drops at the ''magic’ numbers of electrons. These numbers are equal to 186, 198, 254, 338, 440, 556, 676, 832, 912, 1,284, 1,502, and 1,760, in agreement with various experimental data. We show that the conductivity and capacitance of a metal nanosphere can be changed by several orders of magnitude by adding or removing just a few electrons.     

Rapid and sensitive detection of Salmonella Typhimurium on eggshells by using wireless biosensors

This article presents rapid, sensitive, direct detection of Salmonella Typhimurium on eggshells by using wireless magnetoelastic (ME) biosensors. The biosensor consists of a freestanding, strip-shaped ME resonator as the signal transducer and the E2 phage as the biomolecular recognition element that selectively binds with Salmonella Typhimurium. This ME biosensor is a type of mass-sensitive biosensor that can be wirelessly actuated into mechanical resonance by an externally applied timevarying magnetic field. When the biosensor binds with Salmonella Typhimurium, the mass of the sensor increases, resulting in a decrease in the sensor's resonant frequency. Multiple E2 phage-coated biosensors (measurement sensors) were placed on eggshells spiked with Salmonella Typhimurium of various concentrations (1.6 to 1.6 × 10(7) CFU/cm(2)). Control sensors without phage were also used to compensate for environmental effects and nonspecific binding. After 20 min in a humidity-controlled chamber (95%) to allow binding of the bacteria to the sensors to occur, the resonant frequency of the sensors was wirelessly measured and compared with their initial resonant frequency. The resonant frequency change of the measurement sensors was found to be statistically different from that of the control sensors down to 1.6 × 10(2) CFU/cm(2), the detection limit for this work. In addition, scanning electron microscopy imaging verified that the measured resonant frequency changes were directly related to the number of bound cells on the sensor surface. The total assay time of the presented methodology was approximately 30 min, facilitating rapid detection of Salmonella Typhimurium without any preceding sampling procedures.     

Coupled aeroelastic oscillations of a turbine blade row in 3D transonic flow

heodctionThe trend of imPrved gas ndine engine designwith higher Hntalc blade loadin and sInallerPhysical size attraCtS much Mon to the aeroelasticbehayour of blades not Ouly in comPI'essors, bu also intuIbines. Flow-induced triine and comPressor bladesoscillations can lead to fatigUe failures of a constrUctionand so rePrsent imPorIant Problems of reliability, safety,and operatin cost.The hahonal aPProach in flutter calculations ofblW disks is based on twency doInain analysis"ro,in whi…     

Fluorescent dye labeled bacteriophages--a new tracer for the investigation of viral transport in porous media: 1. Introduction and characterization

A new method for the study of pathogen transport in porous media is presented. The method is based on conjugation of fluorescent dyes to target bacteriophages and application of the modified bacteriophages for tracer studies. We demonstrate that the relevant transport determining properties of Rhodamine and several fluorescein-labeled phages are practically identical to those of the native bacteriophages. The advantages of the proposed method relative to direct enumeration of bacteriophages by plaque forming unit method, turbidity, fluorescent microspheres, and other alternative tracers are discussed. Notable advantages include simple quantitation by optical methods, unbiased signals even when virus aggregates are formed, and the ability to decouple inactivation kinetics from transport phenomena. Additionally, the signal reflects the removal and transport of the studied microorganism and not a surrogate.     

The specific heat of the cuticle and the morphological differences between the brown and yellow cuticles of hornets

The morphology and thermophysical properties of stripes of brown and yellow cuticle collected from specimens of the Oriental hornet, Vespa orientalis (Hymenoptera, Vespinae), were analysed and compared by scanning and transmission electron microscopy. In the brown cuticle the colour stems from incrustation of the pigment melanin. In the yellow cuticle the yellow coloured pigment is concentrated in pockets between two layers of cuticle and its colour shows through the transparent cuticle. Both brown and yellow cuticles are composed of more than 30 layers. The upper layers are about 1-4 microm thick and as we proceed inwards, they become thinner so that the deepest ones that can still be discerned are thinner than the upper-most layer by one or two orders of magnitude (i.e., x 1/10 - x 1/100). The brown and yellow cuticles are each about 20 microm thick, but owing to the yellow pigment inserted in pockets of the yellow cuticle the total thickness of the latter is about 45 microm. The morphology of the yellow granules that contain the yellow pigment is shown and discussed. Below 20 degrees C and above 40 degrees C the specific heat (Cp) readings for both types of cuticle coincide, their values lying between approximately 1.55 and 1.60 J kg(-1), but in the temperature range 20-40 degrees C, the specific heat of the yellow strips displays a sharply non-monotonic behaviour, attaining a value of Cp = 1.8 J / Kg at 30 degrees, which contrasts with the relatively smooth curve shown by the brown strips. This anomaly (hump) does not occur following preheating of the samples to 70 degrees C. The shape of the repeated (annealed) 'yellow' curve is basically the same as that of the brown curve. The pockets of yellow pigment and their thermal contribution can be evaluated quantitatively by integration and correspond to an enthalpy of H = 3.5 J g(-1). The difference between the two types of hornet cuticle and the significance of this difference is discussed.     

Coupled multipolar interactions in small-particle metallic clusters

We propose a new formalism for computing the optical properties of small clusters of particles. It is a generalization of the coupled dipole-dipole particle-interaction model and allows one in principle to take into account all multipolar interactions in the long-wavelength limit. The method is illustrated by computations of the optical properties of N = 6 particle clusters for different multipolar approximations. We examine the effect of separation between particles and compare the optical spectra with the discrete-dipole approximation and the generalized Mie theory.     

Method of spectral compensation and its application in the ultraviolet for sulfur dioxide control with a gas-filter correlation instrument

Changes in structureless spectra that are due to the presence of interfering absorbers or light source instabilities, changes in the spectral transfer function of the optics, and changes in the detector's spectral responsivity degrade measurement accuracy. A method of compensating for changes in structureless spectra is developed for a gas-filter correlation instrument. It is shown that there are points in the spectrum where the effect of the interfering component's having a structureless spectrum on the measurement can be drastically reduced.     

Ontogenesis of peripheral electromagnetic receptors in hornets

This article traces the ontogenesis of peripheral electromagnetic receptors (PER) in the cuticle of the Oriental hornet (Vespa orientalis). In the abdominal cuticle of adult hornets, the PERs are densely distributed throughout, but there are even more than 30 at the margins of the segments. These organelles develop as a network in the hornet cuticle immediately upon its completion. Briefly, from each basic cell of a PER grows a bulge towards the exterior, that is, towards the illuminated region of the cuticle. This bulge develops rapidly and as it grows it starts to push out and lift up the various layers of the cuticle, the while pressing them together. By a spiraling movement, the bulge insinuates itself between the layers, whereupon it dissolves and punctures its way through all the layers of the hypocuticle, via the endocuticle up to the exocuticle. The only cuticular layer that remains intact is the epicuticle, but even that undergoes change, assuming the shape of a smooth surface with a depression at its center. The indented part in the epicuticle is circular, approximately 2.5 microm in diameter and enables the entry of radiation (illumination) from the outside into the PER, which is located half-way down the cuticle, with the distance from the exterior to the base of the PER being approximately 25 microm. The numerous lamellae of the cuticle run parallel to one another, but in the region of the bulge they are either perpendicular or directed upwards. This ontogeny of the PERs lends the cuticle a sandwich-like shape, being radically perforated by the PERs bulges, yet covered at the top by the epicuticle and at the bottom by basal cells. The PERs also extend shoots into the cuticular layer and these further perforate the cuticle but also interlink the various PERs. From all the above, it is clear that the cuticle forms first and only subsequently does the network of PERs develop and interpenetrate its various layers.     

Ultraviolet-visible imaging acousto-optic tunable filters in KDP

There is a need to develop large-aperture acousto-optic tunable filters (AOTFs) in the UV region for applications in astronomy, environmental sciences, biology, etc. We have developed a high-quality noncollinear AOTF cell that uses a single crystal of KDP that has nearly a four times larger acousto-optic figure of merit, M2, than quartz. The linear and angular apertures of this cell are 1.5 cm x 1.5 cm and 1.2 degrees, respectively. The spectral range is 220-480 nm, with 160-cm(-1) spectral resolution and high transmission in the UV. We present an analysis of the design and describe the characterization results.