Two smoothing strategies combined with autoregressive integrated moving average (ARIMA) and autoregressive neural networks (ANNs) models to improve the forecasting of time series are presented. The strategy of forecasting is implemented using two stages. In the first stage the time series is smoothed using either, 3-point moving average smoothing, or singular value Decomposition of the Hankel m...

BACKGROUND Viroids are circular, highly structured, non-protein-coding RNAs that, usurping cellular enzymes and escaping host defense mechanisms, are able to replicate and move through infected plants. Similarly to viruses, viroid infections are associated with the accumulation of viroid-derived 21-24 nt small RNAs (vd-sRNAs) with the typical features of the small interfering RNAs characteristi...

This study concerns parameterization and subsequent subtraction of the fast decaying signals of macromolecules from in vivo MRS signals of tissue metabolites of interest. The parameterization is done with a State Space approach (HSVD) based on singular value decomposition. The method is tested with a simulated non-exponentially damped macromolecule signal and an exponentially damped metabolite ...

Citrus Bent Leaf Viroid (CBLVd) and Dwarfing (CDVd), from genus Apscaviroid, are two of the widely distributed citrus viroids among eight reported to date. They have been found induce reduction in canopy volume fruit production trees on trifoliate orange hybrids rootstocks. Moreover, infected only with CBLVd or combinations Exocortis (CEVd), Hop Stunt (HSVd) CDVd associated a poor development r...

Background and Aims: Plant certification programs need reliable, fast, cheap and sensitive methods for detection of systemic pathogens with special interest in virus and viroid detection. Reverse transcriptase-polymerase chain reaction (RT-PCR) has been documented as an alternative assay for certification of plant propagating materials. The main object of the present study was the optimization ...

Figure 1 Figure 2 Citrus fruits are traditional agricultural products in Egypt. Citrus volkameriana is the best rootstock for growing citrus in Egypt’s desert areas (newly reclaimed land). It is far superior to other rootstocks used in Egypt in its resistance to Citrus tristeza virus as well as its tolerance to drought. Constraints to fruit production are mainly related to tree decline caused b...