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Mutually unbiased bases (MUBs) play a key role in many protocols in quantum science, such as quantum key distribution. However, defining MUBs for arbitrary high-dimensional systems is theoretically difficult, and measurements in such bases can be hard to implement. We show experimentally that efficient quantum state reconstruction of a high-dimensional multi-partite quantum system can be performed by considering only the MUBs of the individual parts. The state spaces of the individual subsystems are always smaller than the state space of the composite system. Thus, the benefit of this method is that MUBs need to be defined for the small Hilbert spaces of the subsystems rather than for the large space of the overall system. This becomes especially relevant where the definition or measurement of MUBs for the overall system is challenging. We illustrate this approach by implementing measurements for a high-dimensional system consisting of two photons entangled in the orbital angular momentum (OAM) degree of freedom, and we reconstruct the state of this system for dimensions of the individual photons from d=2 to 5., Comment: 8 pages

We report the entanglement of topological features, namely, isolated, linked optical vortex loops in the light from spontaneous parametric down-conversion (SPDC). In three dimensions, optical vortices are lines of phase singularity and vortices of energy flow which percolate through all optical fields. This example of entanglement is between features that extend over macroscopic and finite volumes, furthermore, topological features are robust to perturbation . The entanglement of photons in complex three-dimensional(3D) topological states suggests the possibility of entanglement of similar structures in other quantum systems describable by complex scalar functions, such as superconductors, superfluids and Bose-Einstein condensates.

We measure hydrodynamic interactions between colloidal particles confined in a thin sheet of fluid. The reduced dimensionality, compared to a bulk fluid, increases dramatically the range of couplings. Using optical tweezers we force a two body system along the eigenmodes of the mobility tensor and find that eigen-mobilities change logarithmically with particle separation. At a hundred radii distance, the mobilities for correlated and anti-correlated motions differ by a factor of two, whereas in bulk fluids, they would be practically indistinguishable. We derive the two dimensional counterpart of the Oseen hydrodynamic tensor which quantitatively reproduces the observed behavior. These results highlight the importance of dimensionality for transport and interactions in colloidal systems and proteins in biological membranes., Comment: 5 pages, 3 figures

The Brownian dynamics of an optically trapped water droplet are investigated across the transition from over to under-damped oscillations. The spectrum of position fluctuations evolves from a Lorentzian shape typical of over-damped systems (beads in liquid solvents), to a damped harmonic oscillator spectrum showing a resonance peak. In this later under-damped regime, we excite parametric resonance by periodically modulating the trapping power at twice the resonant frequency. The power spectra of position fluctuations are in excellent agreement with the obtained analytical solutions of a parametrically modulated Langevin equation., Comment: 5 pages, 4 figures

We study the phase--space of FLRW models derived from Scalar--Tensor Gravity where the non--minimal coupling is $F(\phi)=\xi\phi^2$ and the effective potential is $V(\phi)=\lambda \phi^n$. Our analysis allows to unfold many feature of the cosmology of this class of theories. For example, the evolution mechanism towards states indistinguishable from GR is recovered and proved to depend critically on the form of the potential $V(\phi)$. Also, transient almost--Friedmann phases evolving towards accelerated expansion and unstable inflationary phases evolving towards stable ones are found. Some of our results are shown to hold also for the String-Dilaton action., Comment: 25 pages, 4 figures, 12 tables, submitted to CQG

We propose a versatile optical ring lattice suitable for trapping cold and quantum degenerate atomic samples at discrete angular positions. We demonstrate the realisation of intensity patterns generated from Laguerre-Gauss ($\exp(i \ell\theta)$) modes with different $\ell$ indices. The ring lattice can have either intensity maxima or minima, suitable for trapping in red or blue detuned light, and it can be rotated by introducing a frequency shift between the Laguerre Gauss modes. The potential wells can be joined to form a uniform ring trap, making it ideal for studying persistent currents and the Mott insulator transition in a ring geometry., Comment: 4 pages, 4 figures

Optical vortices generically arise when optical beams are combined. Recently, we reported how several laser beams containing optical vortices could be combined to form optical vortex loops, links and knots embedded in a light beam (Leach et al 2004). Here, we describe in detail the experiments in which vortex loops form these structures. The experimental construction follows a theoretical model originally proposed by Berry and Dennis, and the beams are synthesised using a programmable spatial light modulator and imaged using a CCD camera., Comment: 11 pages, 6 figures

The Georgia Teacher Certification Tests were developed and validated to be job-related and to reflect the minimum content knowledge that is necessary to teach in each certification area in Georgia classrooms. Three assessment instruments are used in evaluating the performance of preservice students and beginning teachers. The Teacher Performance Assessment Instrument (TPAI) delineates 14 competencies required for certification. The Georgia Teachers Certification Tests (TCT) are used to determine whether prospective teachers possess essential knowledge in their respective teaching fields. The on-the-job assessment focuses on the teacher's capabilities to organize, plan, and implement instruction as well as on classroom management and interpersonal relationships with students. Each of these instruments is described in detail in this report. Included in the discussion on performance-based certification are brief descriptions of staff development processes and teacher evaluation. It is anticipated that performance-based certification will be expanded in the future and that a competitive and market sensitive career ladder program for teachers will be developed. (JD)

The rice bacterial blight pathogen Xanthomonas oryzae pv. oryzae is a vascular pathogen that elicits a defensive response through interaction with metabolically active rice cells. In leaves of 12-day-old rice seedlings, the exposed pit membrane separating the xylem lumen from the associated parenchyma cells allows contact with bacterial cells. During resistant responses, the xylem secondary walls thicken within 48 h and the pit diameter decreases, effectively reducing the area of pit membrane exposed for access by bacteria. In susceptible interactions and mock-inoculated controls, the xylem walls do not thicken within 48 h. Xylem secondary wall thickening is developmental and, in untreated 65-day-old rice plants, the size of the pit also is reduced. Activity and accumulation of a secreted cationic peroxidase, PO-C1, were previously shown to increase in xylem vessel walls and lumen. Peptide-specific antibodies and immunogold-labeling were used to demonstrate that PO-C1 is produced in the xylem parenchyma and secreted to the xylem lumen and walls. The timing of the accumulation is consistent with vessel secondary wall thickening. The PO-C1 gene is distinct but shares a high level of similarity with previously cloned pathogen-induced peroxidases in rice. PO-C1 gene expression was induced as early as 12 h during resistant interactions and peaked between 18 and 24 h after inoculation. Expression during susceptible interactions was lower than that observed in resistant interactions and was undetectable after infiltration with water, after mechanical wounding, or in mature leaves. These data are consistent with a role for vessel secondary wall thickening and peroxidase PO-C1 accumulation in the defense response in rice to X. oryzae pv. oryzae.

The influence of microgravity on the susceptibility of soybean roots to Phytophthora sojae was studied during the Space Shuttle Mission STS-87. Seedlings of soybean cultivar Williams 82 grown in spaceflight or at unit gravity were untreated or inoculated with the soybean root rot pathogen P. sojae. At 3, 6 and 7 d after launch while still in microgravity, seedlings were photographed and then fixed for subsequent microscopic analysis. Post-landing analysis of the seedlings revealed that at harvest day 7 the length of untreated roots did not differ between flight and ground samples. However, the flight-grown roots infected with P. sojae showed more disease symptoms (percentage of brown and macerated areas) and the root tissues were more extensively colonized relative to the ground controls exposed to the fungus. Ethylene levels were higher in spaceflight when compared to ground samples. These data suggest that soybean seedlings grown in microgravity are more susceptible to colonization by a fungal pathogen relative to ground controls.

Plants grown in spaceflight conditions are more susceptible to colonization by plant pathogens. The underlying causes for this enhanced susceptibility are not known. Possibly the formation of structural barriers and the activation of plant defense response components are impaired in spaceflight conditions. Either condition would result from altered gene expression of the plant. Because of the tools available, past studies focused on a few physiological responses or biochemical pathways. With recent advances in genomics research, new tools, including microarray technologies, are available to examine the global impact of growth in the spacecraft on the plant's gene expression profile. In ground-based studies, we have developed cDNA subtraction libraries of rice that are enriched for genes induced during pathogen infection and the defense response. Arrays of these genes are being used to dissect plant defense response pathways in a model system involving wild-type rice plants and lesion mimic mutants. The lesion mimic mutants are ideal experimental tools because they erratically develop defense response-like lesions in the absence of pathogens. The gene expression profiles from these ground-based studies will provide the molecular basis for understanding the biochemical and physiological impacts of spaceflight on plant growth, development and disease defense responses. This, in turn, will allow the development of strategies to manage plant disease for life in the space environment.

A Xanthomonas oryzae pv. oryzae gene with sequence similarity to an Escherichia coli phosphate-binding protein gene (phoS) produces a periplasmic protein of apparent M(r) 35,000 when expressed in E. coli. Amino terminal sequencing revealed that a signal peptide is removed during transport to the periplasm in E. coli.

Observations of polarization of moderately hard X-rays in solar flares are reviewed and compared with the predictions of recent detailed modeling of hard X-ray bremsstrahlung production by non-thermal electrons. The recent advances in the complexity of the modeling lead to substantially lower predicted polarizations than in earlier models and more fully highlight how various parameters play a role in determining the polarization of the radiation field. The new predicted polarizations are comparable to those predicted by thermal modeling of solar flare hard X-ray production, and both are in agreement with the observations. In the light of these results, new polarization observations with current generation instruments are proposed which could be used to discriminate between non-thermal and thermal models of hard X-ray production in solar flares.

A technique for determining the physical arrangement of a solar flare during the impulsive phase was developed based upon a nonthermal model interpretation of the emitted hard X-rays. Accurate values are obtained for the flare parameters, including those which describe the magnetic field structure and the beaming of the energetic electrons, parameters which have hitherto been mostly inaccessible. The X-ray intensity height structure can be described readily with a single expression based upon a semi-empirical fit to the results from many models. Results show that the degree of linear polarization of the X-rays from a flaring loop does not exceed 25 percent and can easily and naturally be as low as the polarization expected from a thermal model. This is a highly significant result in that it supersedes those based upon less thorough calculations of the electron beam dynamics and requires that a reevaluation of hopes of using polarization measurements to discriminate between categories of flare models.

Correlations between X-ray and type 3 radio emission of solar bursts are described through a bivariate distribution function. Procedures for determining the form of this distribution are described. A model is constructed to explain the correlation between the X-ray spectral index and the ratio of X-ray to radio intensities. Implications of the model are discussed. Previously announced in STAR as N82-32243

The significance of low hard X-ray polarization measurements for non-thermal models is discussed. Such a low polarization result, it is shown, can in fact occur in non-thermal models, and the ways in which the degree of X-ray polarization is correlated with the parameters of these models is discussed.

The results of an investigation into the electron distribution in the general non-thermal models of solar flares were used to calculate the characteristics of the impulsive hard X-rays. The height distribution, the spectrum, the polarization, and directivity of the X-rays were observed and how these X-ray characteristics are affected by the parameters defining the model was investigated. An expression is obtained for the X-ray intensity as a function of source height which is an excellent fit under certain constraints. Some available data with spatial resolution are examined and it is shown that it is possible to reproduce these data adequately with the non-thermal model and to determine the values of the parameters describing the flares. Previously announced in STAR as N82-34328

Correlations between X-ray and type 3 radio emission of solar bursts are described through a bivariate distribution function. Procedures for determining the form of this distribution are described. A model is constructed to explain the correlation between the X-ray spectral index and the ratio of X-ray to radio intensities. Implications of the model are discussed.

The results of an investigation into the electron distribution in the general non-thermal models of solar flares were used to calculate the characteristics of the impulsive hard X-rays. The height distribution, the spectrum, the polarization, and directivity of the X-rays were observed and how these X-ray characteristics are affected by the parameters defining the model was investigated. An expression is obtained for the X-ray intensity as a function of source height which is an excellent fit under certain constraints. Some available data with spatial resolution are examined and it is shown that it is possible to reproduce these data adequately with the non-thermal model and to determine the values of the parameters describing the flares.

The models describing the operative physical processes occurring during the impulsive phase of a solar flare can be broadly classified as thermal or nonthermal models. The current investigation is part of a series of studies which analyze the general characteristics of the 'nonthermal' models. The results are presented of an analysis regarding the steady state distribution of energetic electrons within the flare plasma. The time independent Fokker-Planck equation is used to determine the steady state distribution of the electrons in the ambient plasma. The model investigated encompasses thick-target, thin-target, and trap aspects of nonthermal hard X-ray models. High energy electrons with some initial energy spectrum and pitch angle distribution are injected at a height above the photosphere either into a closed magnetic loop structure or into an open field structure. Some approximate analytic solutions are discussed and the results of a numerical analysis are presented.

The variation along a magnetic field line of the energy and pitch angle distribution of high energy electrons injected into a cold hydrogen plasma containing either an open or closed magnetic field structure was investigated. The problem is formulated as a time independent Fokker-Planck Equation for the electron number distribution as a function of the electron energy, electron pitch angle, and the structure of the global magnetic field. Simple analytic solution valid in the small pitch angle regime and for slowly varying magnetic field is presented. For the more general situation a numerical code for solving the Fokker-Planck Equation was used and it was found that the analytic expression agrees well with the numerical results to values of the pitch angle much larger than expected. For most practical applications, one many confidently use the analytic expression instead of having to resort to lengthy numerical computations. These results are useful in the study of the nonthermal models of the impulsive phase of solar flares.

This paper discusses development of a Self-Contained Heat Rejection Module (SHRM) which can be used on a wide variety of future spacecraft launched by the space shuttle orbiter. The SHRM contains radiators which are deployed by a scissor-mechanism and the flow equipment including pumps, accumulator, by-pass valves, and controllers necessary to reject heat from those radiators. Heat transfer between SHRM and the parent vehicle is effected by a contact heat exchanger. This device provides heat transfer between two separate flow loops through a mechanical connection. This approach reduces the time required to attach the SHRM to the payload, and increases the reliability of the SHRM flow loop since breaking into the fluid system in the field is not required. The SHRM concept also includes a refrigeration system to increase heat rejection capacity in adverse environments, or to provide for a lower return temperature, down to -23 C.

Design requirements for spacecraft heat rejection systems are identified, and their impact on the construction of conventional pumped fluid and hybrid heat pipe/pumped fluid radiators is evaluated. Heat rejection systems to improve the performance or reduce the cost of the spacecraft are proposed. Heat rejection requirements which are large compared to those of existing systems and mission durations which are relatively long, are discussed.

Results of trade studies comparing optimum pumped fluid and hybrid heat pipe/pumped fluid radiator designs are presented. Design variables considered in the system optimization analyses include transport fluid properties and Reynolds number, pump loop component reliabilities, micrometeoroid protection, heat pipe spacing, manifolding and flow routing in pumped fluid designs, transport tubing spacing and diameters, and radiator fin parameters. Criteria for evaluating candidate radiator system designs include mass, radiator area, and overall system reliability. The studies show advantages in constructing large systems from small independent subsystems with oversizing to account for subsystem failures. The optimum size and survivability of the subsystems are identified as a function of the radiator construction, the system heat rejection requirements, the mission duration, and the system reliability requirements.

A lightweight flexible radiator system for on-orbit cooling of space payloads is described. The radiator is packaged as a compact unit which can be attached to a vehicle structure or hatch prior to or after launch. On-orbit, it is deployed to provide the radiating surface needed for a specific experiment. The unit is being independently developed and qualified as a heat rejection system which will be ready for any spacecraft or experiment, and which will not require significant structural and systems accommodation. Design details and thermal vacuum test results are presented.

Prototypes of two types of modularized, deployable radiator systems with a high degree of configuration and component commonality to minimize design, development and fabrication costs are currently under development for Shuttle payloads with high waste heat: a rigid radiator system which utilizes aluminum honeycomb panels that are deployed by a scissors mechanism; and two 'flexible' radiator systems which use panels constructed from flexible metal/dielectric composite materials that are deployed by 'unrolling' or 'extending' in orbit. Detail descriptions of these deployable radiator systems along with design and performance features are presented.

Conceptual designs of an inflatable radiator system developed for supplying short duration supplementary cooling of space vehicles are described along with parametric trade studies, materials evaluation/selection studies, thermal and structural analyses, and numerous element tests. Fabrication techniques developed in constructing the engineering models and performance data from the model thermal vacuum tests are included. Application of these data to refining the designs of the flight articles and to constructing a full scale prototype radiator is discussed.