Wavelet compression techniques for hyperspectral data

Hyperspectral sensors are electro-optic sensors which typically operate in visible and near infrared bands. Their characteristic property is the ability to resolve a relatively large number (i.e., tens to hundreds) of contiguous spectral bands to produce a detailed profile of the electromagnetic spectrum. In contrast, multispectral sensors measure relatively few non-contiguous spectral bands. Like multispectral sensors, hyperspectral sensors are often also imaging sensors, measuring spectra over an array of spatial resolution cells. The data produced may thus be viewed as a three dimensional array of samples in which two dimensions correspond to spatial position and the third to wavelength. Because they multiply the already large storage/transmission bandwidth requirements of conventional digital images, hyperspectral sensors generate formidable torrents of data. Their fine spectral resolution typically results in high redundancy in the spectral dimension, so that hyperspectral data sets are excellent candidates for compression. Although there have been a number of studies of compression algorithms for multispectral data, we are not aware of any published results for hyperspectral data. Three algorithms for hyperspectral data compression are compared. They were selected as representatives of three major approaches for extending conventional lossy image compression techniques to hyperspectral data. The simplest approach treats the data as an ensemble of images and compresses each image independently, ignoring the correlation between spectral bands. The second approach transforms the data to decorrelate the spectral bands, and then compresses the transformed data as a set of independent images. The third approach directly generalizes two-dimensional transform coding by applying a three-dimensional transform as part of the usual transform-quantize-entropy code procedure. The algorithms studied all use the discrete wavelet transform. In the first two cases, a wavelet transform coder was used for the two-dimensional compression. The third case used a three dimensional extension of this same algorithm

Quantifying the CDK inhibitor VMY-1-103\u27s activity and tissue levels in an in vivo tumor model by LC-MS/MS and by MRI.

The development of new small molecule-based therapeutic drugs requires accurate quantification of drug bioavailability, biological activity and treatment efficacy. Rapidly measuring these endpoints is often hampered by the lack of efficient assay platforms with high sensitivity and specificity. Using an in vivo model system, we report a simple and sensitive liquid chromatography-tandem mass spectrometry assay to quantify the bioavailability of a recently developed novel cyclin-dependent kinase inhibitor VMY-1-103, a purvalanol B-based analog whose biological activity is enhanced via dansylation. We developed a rapid organic phase extraction technique and validated wide and functional VMY-1-103 distribution in various mouse tissues, consistent with its enhanced potency previously observed in a variety of human cancer cell lines. More importantly, in vivo MRI and single voxel proton MR-Spectroscopy further established that VMY-1-103 inhibited disease progression and affected key metabolites in a mouse model of hedgehog-driven medulloblastoma

Conversión de prueba cutánea de derivado proteico purificado durante el tratamiento con anti-TNF-α

Introducción: los anti-TNF-α se asocian con mayor riesgo de desarrollar tuberculosis (TB). La prueba del derivado proteico purificado (purified protein derivative, PPD) se emplea para diagnosticar infección de tuberculosis latente (ITL). Se recomienda el cribado para TB previo al inicio de terapia anti-TNF-α y el seguimiento para evaluar la posible conversión de la PPD durante el tratamiento. El tratamiento de la ITL puede reducir el riesgo de desarrollar enfermedad activa en un 90%. Objetivos: actualmente los resultados de conversión de la PPD y su interpretación durante el tratamiento anti-TNF-α son variables, por tal motivo nos propusimos conocer la frecuencia de conversión de la PPD en este grupo de pacientes de nuestro medio

Care recipients’ physical frailty is independently associated with subjective burden in informal caregivers in the community setting: a cross-sectional study

Abstract Background Physical frailty is associated with significant morbidity and mortality in community-dwelling older adults. Burden in informal caregivers of older adults causes significant physical and psychological distress. However, the relationship between these two clinical phenomena has not been extensively studied. This cross-sectional study evaluated the relationship between physical frailty of community-dwelling older adults attending an outpatient geriatric clinic and the subjective burden reported by their informal caregivers. Methods We measured the following characteristics of 45 patient-caregiver dyads attending an outpatient geriatric assessment clinic: Physical frailty using the Fried Frail Scale (FFS); self-reported independence in activities of daily living (ADL) using the Katz Index; clinical diagnosis of dementia; and subjective caregiver burden using the short 12-item version of the Zarit Burden Interview (ZBI). Multivariable linear regression was performed with FFS, Katz Index score, gender, age, and diagnosis of dementia as independent variables, and ZBI score as the dependent variable. Results Only physical frailty significantly predicted caregiver burden (β = 8.98 95% confidence interval [CI]: 2.15, 15.82). Conclusions Physical frailty is independently associated with caregiver burden in a population of community-dwelling older adults. Despite limitations related to sample size and lack of data about caregiver characteristics, this study suggests that the relationship between physical frailty and caregiver burden merits further study

Global mean cloud feedbacks in idealized climate change experiments

Global mean cloud feedbacks in ten atmosphere-only climate models are estimated in perturbed sea surface temperature (SST) experiments and the results compared to doubled CO2 experiments using mixed-layer ocean versions of these same models. The cloud feedbacks in any given model are generally not consistent: the sign of the net cloud radiative feedback may vary according to the experimental design. However, both sets of experiments indicate that the variation of the total climate feedback across the models depends primarily on the variation of the net cloud feedback. Changes in different cloud types show much greater consistency between the two experiments for any individual model and amongst the set of models analyzed here. This suggests that the SST perturbation experiments may provide useful information on the processes associated with cloud changes which is not evident when analysis is restricted to feedbacks defined in terms of the change in cloud radiative forcing