Testing for spatial autocorrelation: the regressors that make the power disappear

We show that for any sample size, any size of the test, and any weights matrix outside a small class of exceptions, there exists a positive measure set of regression spaces such that the power of the Cli-Ord test vanishes as the autocorrelation increases in a spatial error model. This result extends to the tests that dene the Gaussian power envelope of all invariant tests for residual spatial autocorrelation. In most cases, the regression spaces such that the problem occurs depend on the size of the test, but there also exist regression spaces such that the power vanishes regardless of the size. A characterization of such particularly hostile regression spaces is provided

0.5-50 GHz dielectric characterisation of breast cancer tissues

Cancer affects a significant percentage of people, and early detection techniques are important for prompt and effective treatment. The use of microwave frequencies to achieve non-invasive and non-destructive cancer detections is currently under investigation by several research groups. In this frequency range, the dielectric properties of the biological tissue determine the interactions of the tissue with electromagnetic fields. Knowledge of the dielectric properties of both the normal and the malignant human tissues is therefore a fundamental starting point. A dielectric spectroscopy system, based on the use of a reflectometry setup, was used to perform an extensive experimental campaign on fresh surgical specimens. The measurement system allowed achieving a broadband dielectric characterisation of biological tissues up to 50 GHz, thus including millmetre-wave (mm-wave) frequencies. In the case of breast tissues, the results showed that the malignant and normal tissues exhibit significantly different complex dielectric permittivities of up to 50 GHz, due to their respective high and low water content. This permittivity difference is well detectable, and this paves the way to new screening methods based on mm-wave imaging systems

Cerebellar neurons and glial cells are transducible by lentiviral vectors without decrease of cerebellar functions

Due to the profuse connections of the cerebellum to the rest of the central nervous system, cerebellar dysfunction impacts tremendously on movement coordination, maintenance of equilibrium, muscle tone and motor memory. Efficient gene transfer of therapeutic genes to this central nervous system structure would constitute a relevant step ahead the design of treatments to ameliorate cerebellar dysfunction. Lentiviral vectors (LVs) have been used as efficient vehicles to integrate transgenes into dividing and non-dividing cells, such as postmitotic adult neurons, with minimal toxicity and immune response. This study aimed to use LVs carrying green fluorescent protein (GFP) cDNA for transduction of cerebellar cells in vivo without compromising neurological cerebellar functions. Our results indicate that LVs, injected in the lobulus simplex, transduced different cerebellar neurons including stellate, Purkinje cells, granular neurons and glial cells such as astrocytes, oligodendrocytes, and that this gene transfer approach was not accompanied by cerebellar deficits