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The discovery of single-phase multiferroic materials and the understanding of coupling mechanisms between their spin and polarization is important from the point of view of next generation logic and memory devices. Herein we report the fabrication, dielectric, ferroelectric, piezo-response force microscopy, and magnetization measurements of Pd-substituted room-temperature magnetoelectric multiferroic PbPd0.3Ti0.7O3 (PbPdT) thin films. Highly oriented PbPdT thin films were deposited on {(LaAlO3)0.3(Sr2AlTaO6)0.7} (LSAT) substrates in oxygen atmosphere using pulsed laser deposition technique. X-ray diffraction studies revealed that the films had tetragonal phase with (001) orientation. Surface morphology studies using atomic force and scanning electron microscopy suggest a smooth and homogeneous distribution of grains on the film surface with roughness ~2 nm. A large dielectric constant of ~1700 and a low-loss tangent value of ~0.3 at 10 kHz were obtained at room temperature. Temperature dependent dielectric measurements carried out on Pt/PbPdT/La0.7Sr0.3MnO3 (LSMO) metal-dielectric-metal capacitors suggest a ferroelectric to paraelectric transition above 670 K. The measured polarization hysteresis loops at room temperature were attributed to its ferroelectric behavior. From a Tauc plot of (αhν)2 versus energy, the direct band gap Eg of PbPdT thin films was calculated as 3 eV. Ferroelectric piezoelectric nature of the films was confirmed from a strong domain switching response revealed from piezo-response force microscopy. A well-saturated magnetization M-H loop with remanent magnetization of 3.5 emu/cm3 was observed at room temperature, and it retains ferromagnetic ordering in the temperature range 5-395 K. Origin of the magnetization could be traced to the mixed oxidation states of Pd2+/Pd4+ dispersed in polar PbTiO3 matrix, as revealed by our x-ray photoelectron spectroscopic results. These results suggest that PbPdT thin films are multiferroic (ferroelectric-ferromagnetic) at room temperature.

Snow and urban land cover are important due to their role in hydrological management and utility, climate response, social aspects and economic viability, along with influencing the Earth's environment at local, regional and global scale. Hyperspectral data enable identification, characterization and retrieval of these land-cover features based on physical and chemical properties of compositional materials. AVIRISNG hyperspectral airborne data, with synchronous ground observations using field spectroradiometer and collateral instruments, were collected over two widely varied land-cover types, viz. a relatively homogenous area covered by snow in the extreme cold environment of the Himalaya (Bhaga sub-basin, Himachal Pradesh), and a completely heterogeneous urban area of a metropolitan city (Ahmedabad, Gujarat). AVIRIS-NG airborne data were analysed to understand the effect of terrain parameters such as slope and aspect on snow reflectance. Snow grain index using visible and near-infrared (VNIR) bands and absorption peak in the near-infrared (NIR) were used to retrieve grain size in parts of the Himalayan region. A radiative transfer model was used to understand the grain size variability and its effect on absorption peak in NIR. Continuum removal was performed for snow spectral observations obtained from airborne, modelled and field platforms to estimate band depth at 1030 nm. Grain size was observed to vary with altitude from 100 to 500 μm using AVIRIS-NG image. In the urban area, the data also separated pervious and impervious surface cover using spectral unmixing technique, identified several urban features over multispectral data such as buildings with red tiled roofs, metallic surfaces and tarpaulin sheets using the material spectral profiles. Two single-frame superresolution methods namely sparse regression and natural prior (SRP), and gradient profile prior (GPP) were applied on AVIRIS-NG data for the mixed environment around Kankaria Lake in the city of Ahmedabad, which revealed that SRP method was better than GPP, and affirmed by eight indices. Preliminary analysis of AVIRIS-NG imaging over snow-covered areas and densely populated cities indicated utility of future spaceborne hyperspectral missions, particularly for hydrological and climatological applications in such diverse environments.

Hashem H Ghoraba, Amir Akhavanrezayat, Irmak Karaca, Negin Yavari, Sherin Lajevardi, Jaclyn Hwang, Jonathan Regenold, Wataru Matsumiya, Brandon Pham, Moosa Zaidi, Azadeh Mobasserian, Anthony Toan DongChau, Christopher Or, Cigdem Yasar, Kapil Mishra, Diana Do, Quan Dong Nguyen Spencer Center for Vision Research, Byers Eye Institute, Stanford University, Palo Alto, CA, USACorrespondence: Quan Dong Nguyen, Spencer Center for Vision Research, Byers Eye Institute, Stanford University, 2370 Watson Court, Suite 200, Palo Alto, CA, USA, Tel +1 6507257245, Fax +1 6507368232, Email ndquan@stanford.eduAbstract: Gene therapy has emerged as a research topic of choice in recent years. The eye in particular is one of few organs of the body for which gene therapy has received Food and Drug Administration approval, and it remains a field of great interest for gene therapy development. However, its associated immune and inflammatory reactions may render the treatment ineffective or harmful, which are of particular concern for the eyes due to their susceptibility to inflammation. The severity of immune and inflammatory reactions depends on the choice of vector and its route of administration. Furthermore, most preclinical and clinical studies have shown that the dose of vectors is correlated with the degree of humoral response and ocular inflammation. The route of administration directly impacts the degree of immune and inflammatory reaction. Subretinal delivery produces a weaker humoral response than the intravitreal route. However, some studies have demonstrated that the subretinal delivery induces a stronger inflammatory reaction. On the other hand, several instances of vision loss due to severe late onset intraocular inflammation were reported in a clinical trial involving intravitreal delivery of viral vectors. When compared with the intravitreal route, suprachoroidal gene delivery has been shown to produce weaker humoral response. However, unlike the subretinal space, the suprachoroidal space is not known to have immune privilege status. Inflammatory reactions following ocular gene therapy are typically mild and most clinical and preclinical studies have shown that they can be controlled with topical, local or systemic steroids. However, severe inflammatory responses may occur and require aggressive management to avoid permanent vision loss. Further investigations are required to elucidate and expand our knowledge of inflammatory reactions, and their optimal management, following ocular gene therapy.Keywords: ocular gene therapy, gene therapy, viral vectors, ocular inflammation, review