New Insights on Free Energies and Saint- Venant’s Principle in Viscoelasticity

This work was conceived in 1999 and brought near completion by 2003. Giorgio Gentili was deeply involved in this research until his untimely death. He is greatly missed. Work pressures on the other authors forced a postponement of research on this topic, originally envisaged as lasting a few months but in the event it turned out to be nearly ten years. We now dedicate this work to the memory of Giorgio and to his Family

New Insights on Free Energies and Saint- Venant’s Principle in Viscoelasticity

This work was conceived in 1999 and brought near completion by 2003. Giorgio Gentili was deeply involved in this research until his untimely death. He is greatly missed. Work pressures on the other authors forced a postponement of research on this topic, originally envisaged as lasting a few months but in the event it turned out to be nearly ten years. We now dedicate this work to the memory of Giorgio and to his Family

Zeros of regular functions of quaternionic and octonionic variable: a division lemma and the camshaft effect

We study in detail the zero set of a regular function of a quaternionic or octonionic variable. By means of a division lemma for convergent power series, we find the exact relation existing between the zeros of two octonionic regular functions and those of their product. In the case of octonionic polynomials, we get a strong form of the fundamental theorem of algebra. We prove that the sum of the multiplicities of zeros equals the degree of the polynomial and obtain a factorization in linear polynomials.Comment: Proof of Lemma 7 rewritten (thanks to an anonymous reviewer

Molecular characterization of ‘Candidatus Phytoplasma prunorum’ in Cacopsilla pruni insect vector

Recent investigations on molecular characterization of the ‘Candidatus Phytoplasma prunorum’ (16SrX-B subgroup), causal agent of the European Stone Fruit Yellows (ESFY) syndrome, on the non ribosomal tuf gene resulted in the finding of two groups of isolates, named ‘type a’ and ‘type b’, both with a distinctive geographical distribution in Italian stone fruit growing areas (Ferretti et al., 2007 and 2008). Considering the role of Cacopsylla pruni (Scopoli) in the epidemiological cycle of the disease, the presence of the two groups of isolates has also been investigated in infected psyllid individuals from different Italian areas. Both types have been identified in C. pruni specimens collected on apricot, plum and wild Prunus species, confirming the geographical distribution and the percentages of spread of the two isolates.Keywords: ESFY, phytoplasma, characterization, tuf gene, insect vecto

Identification of Flavescence dorée-related phytoplasma infecting grapevines on the isle of Ischia (southern Italy)

Among the grapevine diseases, Flavescence dorée (FD) is considered to be one of the greatest threats for grapevine cultivation throughout Europe. In Italy, where several major outbreaks of FD have occurred in the past, the disease is still mainly restricted to the northern regions and is under mandatory regulation. In 2011 the disease was recorded for the first time in southern Italy, in several vineyards located on the isle of Ischia (Campania). In order to determine the FD-related phytoplasma infecting these grapevines, molecular investigations were carried out on grapevine samples collected from several FD infected vineyards. The 16S rDNA/spacer region and the FD9 non-ribosomal fragment (secY gene) were investigated using a PCR/RFLP based method; a nucleotide sequence analysis of the FD9 amplified fragments was also carried out. The RFLP profiles obtained from all the analyzed samples showed the presence of FD-D phytoplasma type, on both 16S and secY genomic regions. Sequencing of the FD9 fragments showed a 99 % nucleotide sequence identity among the tested isolates and the various FD-D strains retrieved from the NCBI database.

Evaluation of different peach genotypes for resistance to Plum pox virus

Different responses to the experimental inoculation with a PPV-M isolate were observed in peach germplasm derived from crosses between Prunus persica and peach related species showing resistance to several pathogens. The response evaluation was performed by correlating the phenotypic analysis with serological and molecular tests. Twenty-one individuals, asymptomatic and with low concentration of the virus inside the leaf tissues, have been selected. This germplasm can be considered ‘highly tolerant’ or ‘resistant’ and must be submitted to further investigations.Keywords: PPV, Prunus persica, P. davidiana, P. ferganensis, toleranc

THE INFLUENCE OF VISCO-ELASTIC INSOLES ON GROUND REACTION FORCES DISPLAYED BY ACHILLES TENDONITIS PATIENTS

INTRODUCTION: In our paper we describe the results obtained by quantifying the ground reaction forces with a Kistler force platform of 19 adults affected by achilles tendonitis, before during and after treatment with personalized viscoelastic insoles. Our goal was to quantify the functional deficit determined by that pathology, and quantify the recovery of normal function by treatment with personalized visco-elastic insoles. METHODS: We considered 19 adults athletes (runners) who got achilles tendonitis, to be put in causal relation with their sport activity; they were males and female, 19-63 aged (35 y.o in mean). They all made gait analysis, and the time evolution of the 3 components of ground reaction force was compared with 'normal' ones, so defined in the article by Chao and al. (1983) for healthy female and male adults, that matched with our patients for age, gender and gait velocity. From this comparison we found out some characteristics of the ground reaction of subjects affected by Achilles tendonitis, particularly for what is about the vertical and the antero-posterior components, that are related to the exercise of force on the ground in the first and the last moment of stance, and that for our patients resulted depressed than the normal data. After this first gait analysis the subjects were treated only with personalized visco-elastic insoles, for a mean period of 12 weeks (8 weeks - 6 months), to 'normalize' the foot-ground interaction during stance phase; the gait analysis was repeated at about the mean time of the treatment, and 18 months in mean (12 - 24 months) after his end. RESULTS: This treatment determined not only full remission of symptoms, but a recovery of good functionality of affected lower limbs, as we could verify by repeating gait analysis in the mean time of the treatment, and after 18 months in mean from his end, and performin a statistical elaboration of the data with the Student 't' test. We found that during the treatment functionality improves gradually, and after his end it remaines good, so that visco-elastic insoles resulted effective in avoiding relapses of pathology

Towards ecological flows: status of the benthic macroinvertebrate community during summer low-flow periods in a regulated lowland river

Climate change along with the increasing exploitation of water resources exacerbates low-flow periods, causing detrimental effects on riverine communities. The main mitigation measure currently adopted to counteract hydrological alterations induced by off-stream diversion is the release of minimum flows (MFs), even if within the European Union Water Framework Directive an upgrade towards ecological flows is urgently required to achieve good ecological status (GES). In this study, we investigated the temporal evolution of the benthic macroinvertebrate community in an Italian regulated lowland river (Ticino River) to clarify the ecological effects of summer low flows, and we evaluated the current MFs in the perspective of meeting GES standard. Biomonitoring was carried out for four consecutive years (2019-2022), in a river site immediately below a large off-stream diversion. The four study years were characterized by different streamflow patterns, thus allowing us to compare the temporal trajectories of the community under different flow conditions. Moreover, the interruption of the low-flow periods due to overflow spilled by the upstream dam gave us the opportunity to assess the effects of experimental flow peaks. Contrary to the expectation, the macroinvertebrate assemblage kept almost unvaried across the years, showing great resistance and resilience to hydrological changes. Even in extraordinarily dry 2022, the community composition varied only slightly, with a reduction of mayflies and an increase of mollusks. However, a deterioration of the ecological status below GES standard was recorded that summer, indicating the need for an upgrading of the current MFs. This upgrade would include experimental flow peaks in critical periods, which act as intermediate disturbances, enhancing community richness, diversity, and overall quality, as well as compliance with a threshold of an index specifically developed for the hydrological pressure