Near Infrared

Between 1997 June and 2001 February the Two Micron All Sky Survey (2MASS) collected 25.4 Tbytes of raw imaging data covering 99.998% of the celestial sphere in the near-infrared J (1.25 m), H (1.65 m), and K s (2.16 m) bandpasses. Observations were conducted from two dedicated 1.3 m diameter telescopes located at Mount Hopkins, Arizona, and Cerro Tololo, Chile. The 7.8 s of integration time accumulated for each point on the sky and strict quality control yielded a 10 point-source detection level of better than 15.8, 15.1, and 14.3 mag at the J, H, and K s bands, respectively, for virtually the entire sky. Bright source extractions have 1 photometric uncertainty of <0.03 mag and astrometric accuracy of order 100 mas. Calibration offsets between any two points in the sky are <0.02 mag. The 2MASS All-Sky Data Release includes 4.1 million compressed FITS images covering the entire sky, 471 million source extractions in a Point Source Catalog, and 1.6 million objects identified as extended in an Extended Source Catalog.

Due to strong electric fields at the surface, the absorption and scattering of electromagnetic radiation by noble metal nanoparticles are strongly enhanced. These unique properties provide the potential of designing novel optically active reagents for simultaneous molecular imaging and photothermal cancer therapy. It is desirable to use agents that are active in the near-infrared (NIR) region of the radiation spectrum to minimize the light extinction by intrinsic chromophores in native tissue. Gold nanorods with suitable aspect ratios (length divided by width) can absorb and scatter strongly in the NIR region (650-900 nm). In the present work, we provide an in vitro demonstration of gold nanorods as novel contrast agents for both molecular imaging and photothermal cancer therapy. Nanorods are synthesized and conjugated to anti-epidermal growth factor receptor (anti-EGFR) monoclonal antibodies and incubated in cell cultures with a nonmalignant epithelial cell line (HaCat) and two malignant oral epithelial cell lines (HOC 313 clone 8 and HSC 3). The anti-EGFR antibody-conjugated nanorods bind specifically to the surface of the malignanttype cells with a much higher affinity due to the overexpressed EGFR on the cytoplasmic membrane of the malignant cells. As a result of the strongly scattered red light from gold nanorods in dark field, observed using a laboratory microscope, the malignant cells are clearly visualized and diagnosed from the nonmalignant cells. It is found that, after exposure to continuous red laser at 800 nm, malignant cells require about half the laser energy to be photothermally destroyed than the nonmalignant cells. Thus, both efficient cancer cell diagnostics and selective photothermal therapy are realized at the same time.

3 UPDATES 4 HISTORY 5 PHYSICAL BACKGROUND 6 DESCRIPTION OF ATMOSPHERIC EFFECTS IN SATELLITE OBSERVATIONS 10 ABSTRACT This is the manual for a vector version of the 6S radiative transfer (RT) code (hereafter also referred to as 6SV), capable of accounting for radiation polarization. The manual presents a modified version of the previous scalar 6S manual. For the user's convenience, the format and style of this new manual have been kept as close as possible to those of the previous version. 6S -Second Simulation of a Satellite Signal in the Solar Spectrum -is a basic RT code used for the calculation of look-up tables in the MODIS (MODerate resolution Imaging Spectroradiometer) atmospheric correction algorithm. It enables accurate simulations of satellite and plane observations, accounting for elevated targets, modeling of a realistic molecular/aerosol/ mixed atmosphere, use of Lambertian/anisotropic ground surfaces, and calculation of gaseous absorption. It is one of the most widely used, rigorously validated, and heavily documented RT codes known in the scientific remote-sensing community. The latest updates on the code status (dated May 2005) include a public release of its vector version, 6SV1.0B. As its scalar predecessors, the vector version is based on the method of successive orders of scattering (SOS) approximations. The effects of polarization are included through the calculation of four components of the Stokes vector, characterizing the intensity of radiation, and perpendicular, parallel, and elliptical polarization. The accuracy of RT calculations can be varied by changing the number of calculation angles and layers. By default, 6SV1.0B uses the "standard accuracy" conditions which provide the user with a relative average accuracy of approximately 0.4-0.6%, compared to standard benchmarks and other RT codes.

Quantitation of near infrared spectroscopic data in a scattering medium such as tissue requires knowledge of the optical pathlength in the medium. This can now be estimated directly from the time of flight of picosecond length light pulses. Monte Carlo modelling of light pulses in tissue has shown that the mean value of the time dispersed light pulse correlates with the pathlength used in quantitative spectroscopic calculations. This result has been verified in a phantom material. Time of flight measurements of pathlength across the rat head give a pathlength of 5.3 i 0.3 times the head diameter.

SCIAMACHY (Scanning Imaging Absorption Spectrometer for Atmospheric Chartography) is a spectrometer designed to measure sunlight transmitted, reflected, and scattered by the earth's atmosphere or surface in the ultraviolet, visible, and near-infrared wavelength region (240-2380 nm) at moderate spectral resolution (0.2-1.5 nm, /⌬ ഠ 1000-10 000). SCIAMACHY will measure the earthshine radiance in limb and nadir viewing geometries and solar or lunar light transmitted through the atmosphere observed in occultation. The extraterrestrial solar irradiance and lunar radiance will be determined from observations of the sun and the moon above the atmosphere. The absorption, reflection, and scattering behavior of the atmosphere and the earth's surface is determined from comparison of earthshine radiance and solar irradiance. Inversion of the ratio of earthshine radiance and solar irradiance yields information about the amounts and distribution of important atmospheric constituents and the spectral reflectance (or albedo) of the earth's surface.

We present an atlas of the spectral energy distributions (SEDs) of normal, nonblazar, quasars over the whole available range (radio to 10 keV X-rays) of the electromagnetic spectrum. The primary (UVSX) sample includes 47 quasars for which the spectral energy distributions include X-ray spectral indices and UV data. Of these, 29 are radio quiet, and 18 are radio loud. The SEDs are presented both in figures and in tabular form, with additional tabular material published on CD-ROM. Previously unpublished observational data for a second set of quasars excluded from the primary sample are also tabulated. The effects of host galaxy starlight contamination and foreground extinction on the UVSX sample are considered and the sample is used to investigate the range of SED properties. Of course, the properties we derive are influenced strongly by the selection effects induced by quasar discovery techniques. We derive the mean energy distribution (MED) for radio-loud and radio-quiet objects and present the bolometric corrections derived from it. We note, however, that the dispersion about this mean is large (-one decade for both the infrared and ultraviolet components when the MED is normalized at the near-infrared inflection). At least part of the dispersion in the ultraviolet may be due to time variability, but this is unhkely to be important in the infrared. The existence of such a large dispersion indicates that the MED reflects only some of the properties of quasars and so should be used only with caution. Subject headings: atlases-galaxies: photometry-quasars: general

Depending on the size, the photoluminescence (PL) of silicon quantum dots present in porous silicon can be tuned from the near infrared to the ultraviolet when the surface is passivated with Si-H bonds. After exposure to oxygen, the PL shifts to the red by as much as 1 eV. This shift and the changes in PL intensity and decay time, show that both quantum confinement and surface passivation determine the electronic states of silicon quantum dots. A theoretical model in which new electronic states appear in the band gap of the smaller quantum dots when a Si --O bond is formed, is in good agreement with experiments. This result clarifies the controversy regarding the PL mechanisms in porous silicon.

Dye-sensitized solar cells (DSCs) using titanium dioxide (TiO 2 ) electrodes with different haze were investigated. It was found that the incident photon to current efficiency (IPCE) of DSCs increases with increase in the haze of the TiO 2 electrodes, especially in the near infrared wavelength region. Conversion efficiency of 11.1%, measured by a public test center, was achieved using high haze TiO 2 electrodes. This indicates that raising the haze of TiO 2 electrodes is an effective technique for improvement of conversion efficiency.

Materials whose dielectric constant varies spatially with submicrometer periodicity exhibit diffractive optical properties which are potentially valuable in a number of existing and emerging applications. Here, such systems are fabricated by exploiting the spontaneous crystallization of monodisperse silica spheres into close-packed arrays. By reliance on a vertical deposition technique to pack the spherical colloids into close-packed silica-air arrays, high quality samples can be prepared with thicknesses up to 50 µm. These samples are planar and thus suitable for optical characterization. Scanning electron microscopy (SEM) of these materials illustrates the close-packed ordering of the spherical colloids in planes parallel to the substrate; cross-sectional SEM micrographs of the arrays as well as optical methods are used to measure sample thickness and uniformity. Normal-incidence transmission spectra in the visible and near-infrared regions show distinct peaks due to diffraction from the colloidal layers. While these basic optical characteristics are similar to thicker and polycrystalline gravity-sedimented colloidal crystals, the systematic control over the number of colloidal layers allows the effect of sample thickness on the optical spectrum to be studied for the first time.

The following study examines the feasibility of nanoshell-assisted photo-thermal therapy (NAPT). This technique takes advantage of the strong near infrared (NIR) absorption of nanoshells, a new class of gold nanoparticles with tunable optical absorptivities that can undergo passive extravasation from the abnormal tumor vasculature due to their nanoscale size. Tumors were grown in immune-competent mice by subcutaneous injection of murine colon carcinoma cells (CT26.WT). Polyethylene glycol (PEG) coated nanoshells (≈130 nm diameter) with peak optical absorption in the NIR were intravenously injected and allowed to circulate for 6 h. Tumors were then illuminated with a diode laser (808 nm, 4 W/cm2, 3 min). All such treated tumors abated and treated mice appeared healthy and tumor free >90 days later. Control animals and additional sham-treatment animals (laser treatment without nanoshell injection) were euthanized when tumors grew to a predetermined size, which occurred 6–19 days post-treatment. This simple, non-invasive procedure shows great promise as a technique for selective photo-thermal tumor ablation.

We use a large sample of galaxies from the Two Micron All Sky Survey (2MASS) and the Sloan Digital Sky Survey (SDSS) to calculate galaxy luminosity and stellar mass functions in the local Universe. We estimate corrections for passband shifting and galaxy evolution, as well as present-day stellar mass-to-light (M/L) ratios, by fitting the optical-near-infrared galaxy data with simple models. Accounting for the 8% galaxy overdensity in the SDSS early data release region, the optical and near-infrared luminosity functions we construct for this sample agree with most recent literature optical and near-infrared determinations within the uncertainties. We argue that 2MASS is biased against low surface brightness galaxies, and use SDSS plus our knowledge of stellar populations to estimate the 'true' K-band luminosity function. This has a steeper faint end slope and a slightly higher overall luminosity density than the direct estimate. Furthermore, assuming a universally-applicable stellar initial mass function (IMF), we find good agreement between the stellar mass function we derive from the 2MASS/SDSS data and that derived by Cole et al. (2001; MNRAS, 326, 255). The faint end slope slope for the stellar mass function is steeper than −1.1, reflecting the low stellar M/L ratios characteristic of low-mass galaxies. We estimate an upper limit to the stellar mass density in the local Universe Ω * h = 2.0 ± 0.6 × 10 −3 by assuming an IMF as rich in low-mass stars as allowed by observations of galaxy dynamics in the local Universe. The stellar mass density may be lower than this value if a different IMF with fewer low-mass stars is assumed. Finally, we examine typedependence in the optical and near-infrared luminosity functions and the stellar mass function. In agreement with previous work, we find that the characteristic luminosity or mass of early-type galaxies is larger than for later types, and the faint end slope is steeper for later types than for earlier types. Accounting for typing uncertainties, we estimate that at least half, and perhaps as much as 3/4, of the stellar mass in the Universe is in early-type galaxies. As an aid to workers in the field, we present in an appendix the relationship between model stellar M/L ratios and colors in SDSS/2MASS passbands, an updated discussion of near-infrared stellar M/L ratio estimates, and the volume-corrected distribution of g and K-band stellar M/L ratios as a function of stellar mass.

Brain activity is associated with changes in optical properties of brain tissue. Optical measurements during brain activation can assess haemoglobin oxygenation, cytochrome-c-oxidase redox state, and two types of changes in light scattering reflecting either membrane potential (fast signal) or cell swelling (slow signal), respectively. In previous studies of exposed brain tissue, optical imaging of brain activity has been achieved at high temporal and microscopical spatial resolution. Now, using near-infrared light that can penetrate biological tissue reasonably well, it has become possible to assess brain activity in human subjects through the intact skull non-invasively. After early studies employing single-site near-infrared spectroscopy, first near-infrared imaging devices are being applied successfully for low-resolution functional brain imaging. Advantages of the optical methods include biochemical specificity, a temporal resolution in the millisecond range, the potential of measuring intracellular and intravascular events simultaneously and the portability of the devices enabling bedside examinations.

Nanomaterials that can circulate in the body hold great potential to diagnose and treat disease. For such applications, it is important that the nanomaterials be harmlessly eliminated from the body in a reasonable period of time after they carry out their diagnostic or therapeutic function. Despite efforts to improve their targeting efficiency, significant quantities of systemically administered nanomaterials are cleared by the mononuclear phagocytic system before finding their targets, increasing the likelihood of unintended acute or chronic toxicity. However, there has been little effort to engineer the self-destruction of errant nanoparticles into non-toxic, systemically eliminated products. Here, we present luminescent porous silicon nanoparticles (LPSiNPs) that can carry a drug payload and of which the intrinsic near-infrared photoluminescence enables monitoring of both accumulation and degradation in vivo. Furthermore, in contrast to most optically active nanomaterials (carbon nanotubes, gold nanoparticles and quantum dots), LPSiNPs self-destruct in a mouse model into renally cleared components in a relatively short period of time with no evidence of toxicity. As a preliminary in vivo application, we demonstrate tumour imaging using dextran-coated LPSiNPs (D-LPSiNPs). These results demonstrate a new type of multifunctional nanostructure with a low-toxicity degradation pathway for in vivo applications.

Pre-processing of near-infrared (NIR) spectral data has become an integral part of chemometrics modeling. The objective of the pre-processing is to remove physical phenomena in the spectra in order to improve the subsequent multivariate regression, classification model or exploratory analysis. The most widely used pre-processing techniques can be divided into two categories: scatter-correction methods and spectral derivatives. This review describes and compares the theoretical and algorithmic foundations of current pre-processing methods plus the qualitative and quantitative consequences of their application. The aim is to provide NIR users with better endmodels through fundamental knowledge on spectral pre-processing. ª

Since the Hipparcos mission and recent large scale surveys in the optical and the near-infrared, new constraints have been obtained on the structure and evolution history of the Milky Way. The population synthesis approach is a useful tool to interpret such data sets and to test scenarios of evolution of the Galaxy. We present here new constraints on evolution parameters obtained from the Besançon model of population synthesis and analysis of optical and near-infrared star counts. The Galactic potential is computed self-consistently, in agreement with Hipparcos results and the observed rotation curve. Constraints are posed on the outer bulge structure, the warped and flared disc, the thick disc and the spheroid populations. The model is tuned to produce reliable predictions in the visible and the near-infrared in wide photometric bands from U to K. Finally, we describe applications such as photometric and astrometric simulations and a new classification tool based on a Bayesian probability estimator, which could be used in the framework of Virtual Observatories. As examples, samples of simulated star counts at different wavelengths and directions are also given.

The optoelectronic and physicochemical properties of nanoscale matter are a strong function of particle size. Nanoparticle shape also contributes significantly to modulating their electronic properties. Several shapes ranging from rods to wires to plates to teardrop structures may be obtained by chemical methods; triangular nanoparticles have been synthesized by using a seeded growth process. Here, we report the discovery that the extract from the lemongrass plant, when reacted with aqueous chloroaurate ions, yields a high percentage of thin, flat, single-crystalline gold nanotriangles. The nanotriangles seem to grow by a process involving rapid reduction, assembly and room-temperature sintering of 'liquid-like' spherical gold nanoparticles. The anisotropy in nanoparticle shape results in large near-infrared absorption by the particles, and highly anisotropic electron transport in films of the nanotriangles.

A surface bidirectional reflectance model has been developed for the correction of surface bidirectional effects in time series of satellite observations, where both sun and viewing angles are varying. The model follows a semiempirical approach and is designed to be applicable to heterogeneous surfaces. It contains only three adjustable parameters describing the surface and can potentially be included in an algorithm of processing and correction of a time series of remote sensing data. The model considers that the observed surface bidirectional reflectance is the sum of two main processes operating at a local scale: (1) a diffuse reflection component taking into account the geometrical structure of opaque reflectors on the surface, and shadowing effects, and (2) a volume scattering contribution by a collection of dispersed facets which simulates the volume scattering properties of canopies and bare soils. Detailed comparisons between the model and in situ observations show satisfactory agreement for most investigated surface types in the visible and near-infrared spectral bands. The model appears therefore as a good candidate to reduce substantially the undesirable fluctuations related to surface bidirectional effects in remotely sensed multitemporal data sets.

affecting plant canopy reflectance have been carried out these factors requires an understanding of the sources of over the past few decades, yet the relative importance of variance at each scale (which is ecosystem dependent) as these factors has not been adequately addressed. A comwell as an adequate sampling (spectral, angular, and bination of field and modeling techniques were used to temporal) of the shortwave (400-2500 nm) spectrum. quantify the relative contribution of leaf, stem, and litter ©Elsevier Science Inc., 1998 optical properties (incorporating known variation in foliar biochemical properties) and canopy structural attributes to nadir-viewed vegetation reflectance data. Variability cal properties are a function of leaf structure, water con-Address correspondence to Gregory P. Asner, Univ. of Colorado, tent, and the concentration of biochemicals (Gates et al.,

Gold nanorods prepared in hexadecyltrimethylammonium bromide (CTAB) solution are expected to provide novel materials for photothermal therapy and photo-controlled drug delivery systems. Since gold nanorods stabilized with CTAB show strong cytotoxicity, we developed a technique to modify these with polyethyleneglycol (PEG) for medical applications. PEG-modification was achieved by adding mPEG-SH in the CTAB solution, then, excess CTAB was removed by dialysis. PEG-modified gold nanoparticles showed a nearly neutral surface, and had little cytotoxicity in vitro. Following intravenous injection into mice, 54% of injected PEG-modified gold nanoparticles were found in blood at 0.5 h after intravenous injection, whereas most of gold was detected in the liver in the case of original gold nanorods stabilized with CTAB.

We present the fifth edition of the Sloan Digital Sky Survey (SDSS) Quasar Catalog, which is based upon the SDSS Seventh Data Release. The catalog, which contains 105,783 spectroscopically confirmed quasars, represents the conclusion of the SDSS-I and SDSS-II quasar survey. The catalog consists of the SDSS objects that have luminosities larger than M i = −22.0 (in a cosmology with H 0 = 70 km s −1 Mpc −1 , Ω M = 0.3, and Ω Λ = 0.7), have at least one emission line with FWHM larger than 1000 km s −1 or have interesting/complex absorption features, are fainter than i ≈ 15.0, and have highly reliable redshifts. The catalog covers an area of ≈ 9380 deg 2 . The quasar redshifts range from 0.065 to 5.46, with a median value of 1.49; the catalog includes 1248 quasars at redshifts greater than four, of which 56 are at redshifts greater than five. The catalog contains 9210 quasars with i < 18; slightly over half of the entries have i < 19. For each object the catalog presents positions accurate to better than 0.1 ′′ rms per coordinate, five-band (ugriz) CCD-based photometry with typical accuracy of 0.03 mag, and information on the morphology and selection method. The catalog also contains radio, near-infrared, and X-ray emission properties of the quasars, when available, from other large-area surveys. The calibrated digital spectra cover the wavelength region 3800-9200Å at a spectral resolution of ≃ 2000; the spectra can be retrieved from the SDSS public database using the information provided in the catalog. Over 96% of the objects in the catalog were discovered by the SDSS. We also include a supplemental list of an additional 207 quasars with SDSS spectra whose archive photometric information is incomplete.

We describe biocompatible and nontoxic nanoparticles for in vivo tumor targeting and detection based on pegylated gold nanoparticles and surface-enhanced Raman scattering (SERS). Colloidal gold has been safely used to treat rheumatoid arthritis for 50 years, and has recently been found to amplify the efficiency of Raman scattering by 14-15 orders of magnitude. Here we show that large optical enhancements can be achieved under in vivo conditions for tumor detection in live animals. An important finding is that small-molecule Raman reporters such as organic dyes were not displaced but were stabilized by thiolmodified polyethylene glycols. These pegylated SERS nanoparticles were considerably brighter than semiconductor quantum dots with light emission in the near-infrared window. When conjugated to tumor-targeting ligands such as single-chain variable fragment (ScFv) antibodies, the conjugated nanoparticles were able to target tumor biomarkers such as epidermal growth factor receptors on human cancer cells and in xenograft tumor models.

Optically active nanomaterials promise to advance a range of biophotonic techniques through nanoscale optical effects and integration of multiple imaging and therapeutic modalities. Here, we report the development of porphysomes; nanovesicles formed from self-assembled porphyrin bilayers that generated large, tunable extinction coefficients, structure-dependent fluorescence self-quenching and unique photothermal and photoacoustic properties. Porphysomes enabled the sensitive visualization of lymphatic systems using photoacoustic tomography. Near-infrared fluorescence generation could be restored on dissociation, creating opportunities for low-background fluorescence imaging. As a result of their organic nature, porphysomes were enzymatically biodegradable and induced minimal acute toxicity in mice with intravenous doses of 1,000 mg kg −1 . In a similar manner to liposomes, the large aqueous core of porphysomes could be passively or actively loaded. Following systemic administration, porphysomes accumulated in tumours of xenograft-bearing mice and laser irradiation induced photothermal tumour ablation. The optical properties and biocompatibility of porphysomes demonstrate the multimodal potential of organic nanoparticles for biophotonic imaging and therapy.

The enhanced vegetation index (EVI) was developed as a standard satellite vegetation product for the Terra and Aqua Moderate Resolution Imaging Spectroradiometers (MODIS). EVI provides improved sensitivity in high biomass regions while minimizing soil and atmosphere influences, however, is limited to sensor systems designed with a blue band, in addition to the red and near-infrared bands, making it difficult to generate long-term EVI time series as the normalized difference vegetation index (NDVI) counterpart. The purpose of this study is to develop and evaluate a 2-band EVI (EVI2), without a blue band, which has the best similarity with the 3-band EVI, particularly when atmospheric effects are insignificant and data quality is good. A linearity-adjustment factor β is proposed and coupled with the soil-adjustment factor L used in the soil-adjusted vegetation index (SAVI) to develop EVI2. A global land cover dataset of Terra MODIS data extracted over land community validation and FLUXNET test sites is used to develop the optimal parameter (L, β and G) values in EVI2 equation and achieve the best similarity between EVI and EVI2. The similarity between the two indices is evaluated and demonstrated with temporal profiles of vegetation dynamics at local and global scales. Our results demonstrate that the differences between EVI and EVI2 are insignificant (within ± 0.02) over a very large sample of snow/ice-free land cover types, phenologies, and scales when atmospheric influences are insignificant, enabling EVI2 as an acceptable and accurate substitute of EVI. EVI2 can be used for sensors without a blue band, such as the Advanced Very High Resolution Radiometer (AVHRR), and may reveal different vegetation dynamics in comparison with the current AVHRR NDVI dataset. However, cross-sensor continuity relationships for EVI2 remain to be studied.

Remote sensing of land surface temperature (LST) from the thermal band data of Landsat Thematic Mapper (TM) still remains unused in comparison with the extensive studies of its visible and near-infrared (NIR) bands for various applications. The brightness temperature can be computed from the digital number (DN) of TM6 data using the equation provided by the National Aeronautics and Space Administration (NASA). However, a proper algorithm for retrieving LST from the only one thermal band of the sensor still remains unavailable due to many diYculties in the atmospheric correction. Based on thermal radiance transfer equation, an attempt has been made in the paper to develop a mono-window algorithm for retrieving LST from Landsat TM6 data. Three parameters are required for the algorithm: emissivity, transmittance and eVective mean atmospheric temperature. Method about determination of atmospheric transmittance is given in the paper through the simulation of atmospheric conditions with LOWTRAN 7 program. A practicable approach of estimating eVective mean atmospheric temperature from local meteorological observation is also proposed in the paper when the in situ atmospheric pro le data is unavailable at the satellite pass, which is generally the case in the real world especially for the images in the past. Sensitivity analysis of the algorithm indicates that the possible error of ground emissivity, which is diYcult to estimate, has relatively insigni cant impact on the probable LST estimation error dT , which is sensible to the possible error of transmittance dt 6 and mean atmospheric temperature dT a . Validation of the simulated data for various situations of seven typical atmospheres indicates that the algorithm is able to provide an accurate LST retrieval from TM6 data. The LST diVerence between the retrieved and the simulated ones is less than 0.4°C for most situations. Application of the algorithm to the sand dunes across the Israel-Egypt border results in a reasonable LST *Current address of Z. Qin is SMC, the Spatial Modelling Center, Z. Qin et al. 3720 estimation of the region. Based on this LST estimation, spatial variation of the interesting thermal phenomenon has been analysed for comparison of LST diVerence across the border. The result shows that the Israeli side does have signi cantly higher surface temperature in spite of its denser vegetation cover than the Egyptian side where bare sand is prevalent. 1997 ). The actual use of LST retrieved from Landsat TM6 is few ). In addition to its intrinsic weaknesses (no on-board calibration, low repeat frequency, and so on), the lack of a proper and easily-used algorithm for retrieval of LST from the only one thermal band of Landsat TM data probably is also the main reason leading to the few application.

A new grid of 65 faint near-infrared standard stars is presented. They are spread around the sky, lie between 10th and 12th mag at K, and are measured to precisions better than 0.005 mag in the J, H, K and Ks bands; the latter is a medium-band modi ed K. A secondary list of red stars suitable for determining color transformations between photometric systems is also presented.

We present new remote sensing indices of plant water status: the ratio between the reflectance at 970 nm, one of the water absorption bands, and the reflectance at a reference wavelength, 900 nm (R970/R9000; the first derivative minimum in this near-infrared region (dNIRminimum) and the wavelength where this minimum is found ( λNIRminimum). In order to evaluate them, we carried out three experiments. Daily irrigated gerbera plants were allowed to dry until almost wilting and then daily irrigation was restarted; pepper and bean plants were grown for four months submitted to two different irrigation treatments; and bean detached leaves were submitted to progressive dehydration whereas pressure-volume curves were being carried out.In gerbera plants, the trough about 950–970 nm decreased as the drought was increasing. Therefore, the R970/R900 index and the dNIRminimum closely tracked the changes in relative water content (RWC), leaf water potential, stomatal conductance and the foliage-air temperature differences. The λdNIRminimum tracked even better these changes in gerberas. However, these water status indices began to be significant when the water stress was already well developed, at RWC smaller than 85 per cent. The same happened to detached leaves of beans which did not present differences above −1·55 MPa water potential. Beans and peppers growing at soil matric potentials larger than −0·04 MPa presented higher R970/R900 values than those growing at soil matric potentials only larger than −0·01 MPa.In all the cases, the maximum response of these indices was found in the varieties or the species that lost cell wall elasticity in response to drought stress. This could indicate an important structural component in these indices changes. Relative water content itself seemed to be, however, the most important factor as shown by the highest correlation coefficients with these spectral indices. These spectral signals were more evident at canopy level than at leaf level. They seem to be useful as water status indicators at ground level, especially when there are not important changes of LAI and when plants wholly cover the soil.

The objective of this study was to evaluate near-infrared (NIR) spectroscopic imaging as a tool to assess a pharmaceutical quality assurance problem -blend uniformity in the final dosage product. A system based on array detector technology was used to rapidly collect high-contrast NIR images of furosemide tablets. By varying the mixing, 5 grades of experimental tablets containing the same amount of furosemide and microcrystalline cellulose were produced, ranging from well blended to unblended. For comparison, these tablets were also analyzed by traditional NIR spectroscopy, and both approaches were used to evaluate drug product homogeneity. NIR spectral imaging was capable of clearly differentiating between each grade of blending, both qualitatively and quantitatively. The spatial distribution of the components was based on the variation or contrast in pixel intensity, which is due to the NIR spectral contribution to each pixel. The chemical nature of each pixel could be identified by the localized spectrum associated with each pixel. Both univariate and partial least squares (PLS) images were evaluated. In the suboptimal blends, the regions of heterogeneity were obvious by visual inspection of the images. A quantitative measure of blending was determined by calculating the standard deviation of the distribution of pixel intensities in the PLS score images. The percent standard de-viation increased progressively from 11% to 240% from well blended to unblended tablets. The NIR spectral imaging system provides a rapid approach for acquiring spatial and spectral information on pharmaceuticals. The technique has potential for a variety of applications in product quality assurance and could affect the control of manufacturing processes.

The Multi-angle Imaging SpectroRadiometer (MISR) instrument is scheduled for launch aboard the first of the Earth Observing System (EOS) spacecraft, EOS-AM1. MISR will provide global, radiometrically calibrated, georectified, and co-registered imagery at nine discrete viewing angles and four visiblehear-inf rared spectral bands. Algorithms developed specifically to capitalize on this measurement strategy will be used to retrieve geophysical products for studies of clouds, aerosols, and surface radiation. This paper provides an overview of the as-built instrument characteristics and the application of MISR to remote sensing of the Earth.

We combine the 2MASS extended source catalogue and the 2dF galaxy redshift survey to produce an infrared-selected galaxy catalogue with 17,173 measured redshifts. We use this extensive dataset to estimate the galaxy luminosity functions in the Jand K S -bands. The luminosity functions are fairly well fit by Schechter functions with parameters M ⋆ J − 5 log h = −22.36 ± 0.02, α J = −0.93 ± 0.04, Φ ⋆ J = 0.0104 ± 0.0016h 3 Mpc −3 in the J-band and M ⋆ KS − 5 log h = −23.44 ± 0.03, α KS = −0.96 ± 0.05, Φ ⋆ KS = 0.0108 ± 0.0016h 3 Mpc −3 in the K S -band (2MASS Kron magnitudes). These parameters are derived assuming a cosmological model with Ω 0 = 0.3 and Λ 0 = 0.7. With datasets of this size, systematic rather than random errors are the dominant source of uncertainty in the determination of the luminosity function. We carry out a careful investigation of possible systematic effects in our data. The surface brightness distribution of the sample shows no evidence that significant numbers of low surface brightness or compact galaxies are missed by the survey. We estimate the present-day distributions of b J −K S and J−K S colours as a function of absolute magnitude and use models of the galaxy stellar populations, constrained by the observed optical and infrared colours, to infer the galaxy stellar mass function. Integrated over all galaxy masses, this yields a total mass fraction in stars (in units of the critical mass density) of Ω stars h = (1.6 ± 0.24) × 10 −3 for a Kennicutt IMF and Ω stars h = (2.9 ± 0.43) × 10 −3 for a Salpeter IMF. These values are consistent with those inferred from observational estimates of the total star formation history of the universe provided that dust extinction corrections are modest.

The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) is a high spatial resolution, multispectral imager with alongtrack stereo capabilities scheduled for launch on the first NASA spacecraft of the Earth Observing System (EOS AM-1) in mid-199 . Data will be obtained in 14 spectral bands covering the visible through the < hermal infrared wavelength region. A number of standard data products will be available to requesters through an on-line archival and processing system. Particular, user-specified data acquisitions will be possible through a Data Acquisition Request system. res0000913 06-09-99 2 0 : 5 7 : 4 0 R.-W 1 4 -0 5 r e s 0 0 0 0 9 1 3 0 6 -0 9 -9 9 2 0 : 5 7 : 4 0 R e v 1 4 . 0 5 The Charlesworth Group, Huddersfield 01484 517077

This paper describes a computationally fast and accurate technique for the atmospheric correction of satellite measurements in the solar spectrum. The main advantage of the method is that it is several hundred times faster than more detailed radiative transfer models like 5S and that it does not require precalculated look-up tables. The method is especially useful for correcting the huge amounts of data acquired by large-field-of-view high-repetitivity sensors, like the ones on board polar orbiting and geostationary meteorological satellites. The technique is based on a set of equations with coefficients which depend on the spectral band of the sensor. Semi-empirical formulations are used to describe the different interactions (absorption, scattering, etc.) of solar radiation with atmospheric constituents during its traverse through the atmosphere. Sensor specific coefficients of each equation are determined using a best fit technique against the computations of the 5S code (Simulation of Satellite Signal in the Solar Spectrum, Tame et al. 1990). Other radiative transfer models could be used. Once coefficients for a specific spectral band are determined, the inputs of the model arc vertically integrated gaseous contents, aerosol optical depth at 550 nm, geometric conditions and reflectance at the top of the atmosphere (TOA). TOA reflectances were calculated using our method and then compared to the TOA reflectances calculated by 5S for a wide range of gaseous and aerosol contents, illumination and observation conditions for various sensor spectral bands. In the case of NOAA-9 AVHRR visible data the maximum relative error is 2•35 per cent (i.e. 0•01 for a reflectance value of 0,4) and the corresponding rmse is 0•0018. For NOAA-9 AVHRR near-infrared, Meteosat-I visible, Landsat-5 TM band I and Landsat-5 TM band 4 the maximum relative errors are 3•11, 4'0, 1•65 and 2'37per cent respectively. The corresponding values of the rmse are 0•0022, 0•0015,0,0017 and 0•0012. The method can be used both in the direct and in the inverse mode, i.e., to compute TOA reflectance knowing the surface reflectance (e.g., for fast sensitivity studies), or conversely to retrieve surface reflectance from the TOA reflectance. It can easily be implemented in operational data preprocessing computer code, since only band specific coefficients need to be updated when new sensors are flown, while the routines remain the same.

Raman spectroscopy is a potentially important clinical tool for real-time diagnosis of disease and in situ evaluation of living tissue. The purpose of this article is to review the biological and physical basis of Raman spectroscopy of tissue, to assess the current status of the field and to explore future directions. The principles of Raman spectroscopy and the molecular level

The interactions between artificial nanomaterials and biological systems form an emerging research topic of broad importance. Work in this area is motivated both by the hope that nanomaterials will have useful applications in biology and medicine 1,2 and by the concern that they may exert harmful effects on organisms. Despite the prominence of carbon nanotubes in nanotechnology, exploration of their interactions with biological materials remains at a very early stage. 6 In part, this reflects the challenge of observing nanotubes in biological environments. Single-walled carbon nanotubes (SWNTs) in tissues evade detection by elemental analysis (because they contain only carbon) and electron microscopy (because of low contrast and small diameters). Radiolabeling methods are currently impractical with SWNTs. Recently, SWNTs covalently linked to visible-wavelength fluorophores have been imaged in cells. In this approach, however, the chemical linkage must resist enzymatic cleavage, emission from the visiblewavelength fluorophore must be detected above background endogenous fluorescence, and one must be aware that chemical processing of nanoparticles may dramatically change their biological fate. We present here a method for observing pristine, hydrophobic SWNTs in biological media through their unique near-infrared intrinsic fluorescence. We have selectively detected low concentrations of nanotubes in biological specimens using a spectrofluorometer and a fluorescence microscope modified for near-IR imaging. The unusually long wavelengths of SWNT emission allow high contrast detection with strong discrimination against endogenous fluorescence. We illustrate our technique with near-IR fluorescence spectra, quantitative emission intensities, and microscopic images of mouse macrophagelike cells that have actively ingested nanotubes while incubated in SWNT suspensions. We also find that viability and population growth of these cells are not affected by SWNT exposure under the experimental conditions.

Information on the area and spatial distribution of paddy rice fields is needed for trace gas emission estimates, management of water resources, and food security. Paddy rice fields are characterized by an initial period of flooding and transplanting, during which period open canopy (a mixture of surface water and rice crops) exists. The Moderate Resolution Imaging Spectroradiometer (MODIS) sensor onboard the NASA EOS Terra satellite has visible, near infrared and shortwave infrared bands; and therefore, a number of vegetation indices can be calculated, including Normalized Difference Vegetation Index (NDVI), Enhanced Vegetation Index (EVI) and Land Surface Water Index (LSWI) that is sensitive to leaf water and soil moisture. In this study, we developed a paddy rice mapping algorithm that uses time series of three vegetation indices (LSWI, EVI, and NDVI) derived from MODIS images to identify that initial period of flooding and transplanting in paddy rice fields, based on the sensitivity of LSWI to the increased surface moisture during the period of flooding and rice transplanting. We ran the algorithm to map paddy rice fields in 13 provinces of southern China, using the 8-day composite MODIS Surface Reflectance products (500-m spatial resolution) in 2002. The resultant MODIS-derived paddy rice map was evaluated, using the National Land Cover Dataset (1:100,000 scale) derived from analysis of Landsat ETM+ images in 1999/2000. There were reasonable agreements in area estimates of paddy rice fields between the MODIS-derived map and the Landsat-based dataset at the provincial and county levels. The results of this study indicated that the MODIS-based paddy rice mapping algorithm could potentially be applied at large spatial scales to monitor paddy rice agriculture on a timely and frequent basis. D

Nanocrystals with advanced magnetic or optical properties have been actively pursued for potential biological applications, including integrated imaging, diagnosis and therapy. Among various magnetic nanocrystals, FeCo has superior magnetic properties, but it has yet to be explored owing to the problems of easy oxidation and potential toxicity. Previously, FeCo nanocrystals with multilayered graphitic carbon, pyrolytic carbon or inert metals have been obtained, but not in the single-shelled, discrete, chemically functionalized and water-soluble forms desired for biological applications. Here, we present a scalable chemical vapour deposition method to synthesize FeCo/single-graphitic-shell nanocrystals that are soluble and stable in water solutions. We explore the multiple functionalities of these core-shell materials by characterizing the magnetic properties of the FeCo core and near-infrared optical absorbance of the single-layered graphitic shell. The nanocrystals exhibit ultra-high saturation magnetization, r1 and r2 relaxivities and high optical absorbance in the near-infrared region. Mesenchymal stem cells are able to internalize these nanoparticles, showing high negative-contrast enhancement in magnetic-resonance imaging (MRI). Preliminary in vivo experiments achieve long-lasting positive-contrast enhancement for vascular MRI in rabbits. These results point to the potential of using these nanocrystals for integrated diagnosis and therapeutic (photothermal-ablation) applications.

Based on data obtained at the European Southern Observatory on Paranal, Chile, and at the W.M. Keck Observatory on Mauna Kea, Hawaii. The W.M. Keck Observatory is operated as a scientific partnership among the California Institute of Technology, the University of California, and NASA, and was made possible by the generous financial support of the W.M. Keck Foundation.

We present photometric observations of an apparent Type Ia supernova (SN Ia) at a redshift of D1.7, the farthest SN observed to date. The supernova, SN 1997 †, was discovered in a repeat observation by the Hubble Space T elescope (HST ) of the Hubble Deep Field-North (HDF-N) and serendipitously monitored with NICMOS on HST throughout the Thompson et al. Guaranteed-Time Observer (GTO) campaign. The SN type can be determined from the host galaxy type : an evolved, red elliptical lacking enough recent star formation to provide a signiÐcant population of core-collapse supernovae. The classi-Ðcation is further supported by diagnostics available from the observed colors and temporal behavior of the SN, both of which match a typical SN Ia. The photometric record of the SN includes a dozen Ñux measurements in the I, J, and H bands spanning 35 days in the observed frame. The redshift derived from the SN photometry, z \ 1.7^0.1, is in excellent agreement with the redshift estimate of z \ 1.65^0.15 derived from the photometry of the galaxy.